diff --git a/src/App.css b/src/App.css
index 433fb2b..fbd5d9b 100644
--- a/src/App.css
+++ b/src/App.css
@@ -396,18 +396,18 @@
 
 .app-main {
   display: grid;
-  grid-template-columns: 56px 1fr 300px;
+  grid-template-columns: var(--palette-width) 1fr 300px;
   flex: 1;
   min-height: 0;
   overflow: hidden;
 }
 
 .app-shell[data-layout='desktop'] .app-main {
-  grid-template-columns: 56px 1fr 300px;
+  grid-template-columns: var(--palette-width) 1fr 300px;
 }
 
 .app-shell[data-layout='compact'] .app-main {
-  grid-template-columns: 56px 1fr;
+  grid-template-columns: var(--palette-width) 1fr;
 }
 
 .app-shell[data-layout='touch'] .app-main {
@@ -2601,3 +2601,23 @@ a.statusbar-legal-link {
   min-width: 0;
   flex: 1;
 }
+
+/* The palette keeps a fixed width so the canvas never sits underneath it.
+   Longer translated labels are truncated with an ellipsis (full text is in the tooltip). */
+.tool-palette {
+  box-sizing: border-box;
+  flex: 0 0 var(--palette-width);
+  width: var(--palette-width);
+  min-width: 0;
+  max-width: var(--palette-width);
+  overflow: hidden;
+}
+
+.tool-palette .tool-label {
+  display: block;
+  max-width: 100%;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  text-align: center;
+}
diff --git a/src/components/AnnotationsPanel.tsx b/src/components/AnnotationsPanel.tsx
index ed60b37..69184d7 100644
--- a/src/components/AnnotationsPanel.tsx
+++ b/src/components/AnnotationsPanel.tsx
@@ -11,6 +11,7 @@ import Tooltip from './Tooltip'
 import BottomSheet from './BottomSheet'
 import SlideDrawer from './SlideDrawer'
 import AnnotationAdvertisement from './AnnotationAdvertisement'
+import { useT } from '../i18n'
 
 function AnnotationItem({
   annotation,
@@ -23,6 +24,7 @@ function AnnotationItem({
   selected: boolean
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const setSelectedId = useAppStore((s) => s.setSelectedId)
   const updateAnnotation = useAppStore((s) => s.updateAnnotation)
   const removeAnnotation = useAppStore((s) => s.removeAnnotation)
@@ -60,7 +62,7 @@ function AnnotationItem({
     <button
       type="button"
       className="annotation-delete"
-      aria-label={`Delete annotation ${markerLabel(index)}`}
+      aria-label={t('notes.deleteAria', { label: markerLabel(index) })}
       onClick={(e) => {
         e.stopPropagation()
         removeAnnotation(annotation.id)
@@ -87,7 +89,7 @@ function AnnotationItem({
       {layoutMode === 'touch' ? (
         markerBadge
       ) : (
-        <Tooltip content="Click to center on the map" side="left">
+        <Tooltip content={t('notes.centerHint')} side="left">
           {markerBadge}
         </Tooltip>
       )}
@@ -96,7 +98,7 @@ function AnnotationItem({
           <textarea
             ref={commentInputRef}
             className="annotation-comment-input"
-            placeholder="Add a comment…"
+            placeholder={t('notes.commentPlaceholder')}
             rows={1}
             value={annotation.comment}
             onClick={(e) => e.stopPropagation()}
@@ -108,7 +110,7 @@ function AnnotationItem({
           {layoutMode === 'touch' ? (
             deleteButton
           ) : (
-            <Tooltip content="Remove this marker">{deleteButton}</Tooltip>
+            <Tooltip content={t('notes.removeHint')}>{deleteButton}</Tooltip>
           )}
         </div>
       </div>
@@ -117,6 +119,7 @@ function AnnotationItem({
 }
 
 function MarkerDisplayToggle() {
+  const t = useT()
   const markerDisplayMode = useAppStore((s) => s.markerDisplayMode)
   const setMarkerDisplayMode = useAppStore((s) => s.setMarkerDisplayMode)
 
@@ -127,7 +130,7 @@ function MarkerDisplayToggle() {
       aria-pressed={markerDisplayMode === 'labels'}
       onClick={() => setMarkerDisplayMode('labels')}
     >
-      Labels
+      {t('notes.labels')}
     </button>
   )
 
@@ -138,7 +141,7 @@ function MarkerDisplayToggle() {
       aria-pressed={markerDisplayMode === 'comments'}
       onClick={() => setMarkerDisplayMode('comments')}
     >
-      Comments
+      {t('notes.comments')}
     </button>
   )
 
@@ -146,13 +149,13 @@ function MarkerDisplayToggle() {
     <div
       className="marker-display-toggle"
       role="group"
-      aria-label="Map marker display"
+      aria-label={t('notes.displayAria')}
     >
-      <Tooltip content="Show letter labels on map markers" side="bottom">
+      <Tooltip content={t('notes.labelsHint')} side="bottom">
         {labelsButton}
       </Tooltip>
       <Tooltip
-        content="Show inline comments on the map. Drag the right edge of a selected comment to change its width."
+        content={t('notes.commentsHint')}
         side="bottom"
       >
         {commentsButton}
@@ -166,6 +169,7 @@ function AnnotationsContent({
 }: {
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const annotations = useAppStore((s) => s.annotations)
   const selectedId = useAppStore((s) => s.selectedId)
 
@@ -174,14 +178,14 @@ function AnnotationsContent({
       <div className="panel-header">
         <div className="panel-header-title">
           <MessageSquareText size={16} aria-hidden />
-          <h2>Annotations</h2>
+          <h2>{t('notes.heading')}</h2>
         </div>
         <MarkerDisplayToggle />
       </div>
 
       {annotations.length === 0 ? (
         <p className="panel-empty">
-          No annotations yet. Use the marker tool to add comments to the map.
+          {t('notes.empty')}
         </p>
       ) : (
         <ul className="annotation-list">
@@ -207,6 +211,7 @@ export default function AnnotationsPanel({
   variant: 'sidebar' | 'drawer' | 'sheet'
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const annotations = useAppStore((s) => s.annotations)
   const annotationsOpen = useAppStore((s) => s.annotationsOpen)
   const toggleAnnotations = useAppStore((s) => s.toggleAnnotations)
@@ -229,18 +234,18 @@ export default function AnnotationsPanel({
         <button
           type="button"
           className="annotation-toggle"
-          aria-label="Toggle annotations"
+          aria-label={t('notes.toggleAria')}
           aria-expanded={annotationsOpen}
           onClick={toggleAnnotations}
         >
           <MessageSquareText size={16} aria-hidden />
-          <span>Notes</span>
+          <span>{t('notes.toggle')}</span>
           {annotations.length > 0 && (
             <span className="annotation-toggle-badge">{annotations.length}</span>
           )}
         </button>
         <SlideDrawer
-          title="Annotations"
+          title={t('notes.heading')}
           open={annotationsOpen}
           onClose={closeAnnotations}
         >
@@ -259,7 +264,7 @@ export default function AnnotationsPanel({
 
   return (
     <BottomSheet
-      title="Annotations"
+      title={t('notes.heading')}
       onClose={closeAnnotations}
       className="bottom-sheet-full"
     >
diff --git a/src/components/AppErrorBoundary.tsx b/src/components/AppErrorBoundary.tsx
index 2b5d96e..6366e37 100644
--- a/src/components/AppErrorBoundary.tsx
+++ b/src/components/AppErrorBoundary.tsx
@@ -1,4 +1,5 @@
 import { Component, type ErrorInfo, type ReactNode } from 'react'
+import { t } from '../i18n'
 
 interface Props {
   children: ReactNode
@@ -29,17 +30,14 @@ export default class AppErrorBoundary extends Component<Props, State> {
       return (
         <div className="app-error-boundary" role="alert">
           <div className="app-error-boundary-card">
-            <h2>Something went wrong</h2>
-            <p>
-              O-Analysis ran into an unexpected error. Reloading the page usually
-              fixes this.
-            </p>
+            <h2>{t('error.title')}</h2>
+            <p>{t('error.body')}</p>
             <button
               type="button"
               className="app-error-boundary-reload"
               onClick={this.handleReload}
             >
-              Reload page
+              {t('error.reload')}
             </button>
           </div>
         </div>
diff --git a/src/components/BottomSheet.tsx b/src/components/BottomSheet.tsx
index 0cff55d..b6ae8db 100644
--- a/src/components/BottomSheet.tsx
+++ b/src/components/BottomSheet.tsx
@@ -1,6 +1,7 @@
 import { useEffect, useId, useRef } from 'react'
 import { X } from 'lucide-react'
 import { useEscapeKey } from '../hooks/useEscapeKey'
+import { useT } from '../i18n'
 
 export default function BottomSheet({
   title,
@@ -13,6 +14,7 @@ export default function BottomSheet({
   children: React.ReactNode
   className?: string
 }) {
+  const t = useT()
   const titleId = useId()
   const sheetRef = useRef<HTMLDivElement>(null)
 
@@ -52,7 +54,7 @@ export default function BottomSheet({
             <button
               type="button"
               className="bottom-sheet-close"
-              aria-label="Close"
+              aria-label={t('common.close')}
               onClick={onClose}
             >
               <X size={18} aria-hidden />
diff --git a/src/components/BottomToolBar.tsx b/src/components/BottomToolBar.tsx
index 3caa532..988a68c 100644
--- a/src/components/BottomToolBar.tsx
+++ b/src/components/BottomToolBar.tsx
@@ -5,7 +5,9 @@ import { useAppStore } from '../store'
 import BottomSheet from './BottomSheet'
 import StrokeSettings from './StrokeSettings'
 import CanvasRotationControl from './CanvasRotationControl'
+import { useT } from '../i18n'
 import TextSizeSlider from './TextSizeSlider'
+import LanguageSelect from './LanguageSelect'
 
 export default function BottomToolBar() {
   const activeTool = useAppStore((s) => s.activeTool)
@@ -16,24 +18,25 @@ export default function BottomToolBar() {
   const toggleAnnotations = useAppStore((s) => s.toggleAnnotations)
 
   const [settingsOpen, setSettingsOpen] = useState(false)
+  const t = useT()
 
   return (
     <>
-      <nav className="bottom-toolbar" aria-label="Drawing tools">
+      <nav className="bottom-toolbar" aria-label={t('toolbar.drawingTools')}>
         <div className="bottom-toolbar-tools" role="toolbar">
           {TOOLS.map(({ id, label, shortLabel, icon: Icon }) => (
             <button
               key={id}
               type="button"
               className={`bottom-tool-button${activeTool === id ? ' active' : ''}`}
-              aria-label={label}
+              aria-label={t(label)}
               aria-pressed={activeTool === id}
               title={getToolTip(id, 'touch')}
               disabled={id === 'gpx' && !hasTracks}
               onClick={() => setActiveTool(id)}
             >
               <Icon size={20} aria-hidden />
-              <span className="bottom-tool-label">{shortLabel}</span>
+              <span className="bottom-tool-label">{t(shortLabel)}</span>
             </button>
           ))}
         </div>
@@ -41,22 +44,22 @@ export default function BottomToolBar() {
         <button
           type="button"
           className="bottom-tool-button bottom-tool-extra"
-          aria-label="Stroke settings"
+          aria-label={t('toolbar.strokeSettings')}
           onClick={() => setSettingsOpen(true)}
         >
           <Settings size={20} aria-hidden />
-          <span className="bottom-tool-label">Style</span>
+          <span className="bottom-tool-label">{t('toolbar.style')}</span>
         </button>
 
         <button
           type="button"
           className={`bottom-tool-button bottom-tool-extra${annotationsOpen ? ' active' : ''}`}
-          aria-label="Annotations"
+          aria-label={t('toolbar.annotations')}
           aria-pressed={annotationsOpen}
           onClick={toggleAnnotations}
         >
           <MessageSquareText size={20} aria-hidden />
-          <span className="bottom-tool-label">Notes</span>
+          <span className="bottom-tool-label">{t('toolbar.notes')}</span>
           {annotations.length > 0 && (
             <span className="bottom-tool-badge">{annotations.length}</span>
           )}
@@ -64,9 +67,10 @@ export default function BottomToolBar() {
       </nav>
 
       {settingsOpen && (
-        <BottomSheet title="View & stroke settings" onClose={() => setSettingsOpen(false)}>
+        <BottomSheet title={t('toolbar.viewAndStroke')} onClose={() => setSettingsOpen(false)}>
           <CanvasRotationControl compact />
-          <TextSizeSlider label="Comment text size" className="style-sheet-text-size" />
+          <LanguageSelect className="style-sheet-language" />
+          <TextSizeSlider label={t('style.commentTextSize')} className="style-sheet-text-size" />
           <StrokeSettings layoutMode="touch" />
         </BottomSheet>
       )}
diff --git a/src/components/CanvasArea.tsx b/src/components/CanvasArea.tsx
index f323512..28a01ba 100644
--- a/src/components/CanvasArea.tsx
+++ b/src/components/CanvasArea.tsx
@@ -23,6 +23,7 @@ import {
 } from '../utils/viewport'
 import { getMapPointer } from '../utils/mapPointer'
 import type { Point, Viewport } from '../types'
+import { useT } from '../i18n'
 
 const ZOOM_FACTOR = 1.06
 const WHEEL_COMMIT_MS = 120
@@ -38,6 +39,7 @@ export default function CanvasArea({
 }: {
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const activeTool = useAppStore((s) => s.activeTool)
   const mapImage = useAppStore((s) => s.mapImage)
   const setViewport = useAppStore((s) => s.setViewport)
@@ -618,11 +620,9 @@ export default function CanvasArea({
         <div className="canvas-empty">
           <div className="canvas-empty-card">
             <ImagePlus size={40} aria-hidden />
-            <h2>No map loaded</h2>
+            <h2>{t('canvas.noMap')}</h2>
             <p>
-              {isTouch
-                ? 'Import a map image to get started.'
-                : 'Import a map image to get started, or drop a file here.'}
+              {isTouch ? t('canvas.importHintTouch') : t('canvas.importHintDrop')}
             </p>
             <input
               ref={mapInputRef}
@@ -643,7 +643,7 @@ export default function CanvasArea({
                 onClick={() => mapInputRef.current?.click()}
               >
                 <ImagePlus size={14} aria-hidden />
-                Import Map
+                {t('canvas.importMap')}
               </button>
               <button
                 type="button"
@@ -651,7 +651,7 @@ export default function CanvasArea({
                 disabled={loadingSample}
                 onClick={() => void handleLoadSample()}
               >
-                {loadingSample ? 'Loading sample…' : 'Open Sample Project'}
+                {loadingSample ? t('canvas.loadingSample') : t('canvas.openSample')}
               </button>
             </div>
           </div>
diff --git a/src/components/CanvasRotationControl.tsx b/src/components/CanvasRotationControl.tsx
index ad0e7dc..ae2ee4b 100644
--- a/src/components/CanvasRotationControl.tsx
+++ b/src/components/CanvasRotationControl.tsx
@@ -2,6 +2,7 @@ import { RotateCcw } from 'lucide-react'
 import { useAppStore } from '../store'
 import { stageRef } from '../stageRef'
 import { clampRotation, rotateViewportKeepingCenter } from '../utils/viewport'
+import { useT } from '../i18n'
 
 const MIN_ROTATION = -360
 const MAX_ROTATION = 360
@@ -11,6 +12,7 @@ export default function CanvasRotationControl({
 }: {
   compact?: boolean
 }) {
+  const t = useT()
   const mapImage = useAppStore((s) => s.mapImage)
   const rotation = useAppStore((s) => s.viewport.rotation)
   const setViewport = useAppStore((s) => s.setViewport)
@@ -48,10 +50,10 @@ export default function CanvasRotationControl({
     <div
       className={`canvas-rotation-control${compact ? ' canvas-rotation-control-compact' : ''}`}
       role="group"
-      aria-label="Canvas rotation"
+      aria-label={t('rotation.group')}
     >
       <label className="canvas-rotation-label" htmlFor="canvas-rotation">
-        {compact ? 'Rotation' : 'Rotate'}
+        {compact ? t('rotation.label') : t('rotation.rotate')}
       </label>
       <input
         id="canvas-rotation"
@@ -64,15 +66,15 @@ export default function CanvasRotationControl({
         aria-valuemin={MIN_ROTATION}
         aria-valuemax={MAX_ROTATION}
         aria-valuenow={rotation}
-        aria-valuetext={`${rotation} degrees`}
+        aria-valuetext={t('rotation.degrees', { degrees: rotation })}
         onChange={(e) => applyRotation(Number(e.target.value))}
       />
       <span className="canvas-rotation-value">{rotation}°</span>
       <button
         type="button"
         className="canvas-rotation-reset"
-        aria-label="Reset rotation to 0 degrees"
-        title="Reset rotation"
+        aria-label={t('rotation.resetAria')}
+        title={t('rotation.reset')}
         onClick={() => applyRotation(0)}
       >
         <RotateCcw size={14} aria-hidden />
diff --git a/src/components/ColorPickerModal.tsx b/src/components/ColorPickerModal.tsx
index 9da9f93..e25bdf9 100644
--- a/src/components/ColorPickerModal.tsx
+++ b/src/components/ColorPickerModal.tsx
@@ -1,5 +1,6 @@
 import { useCallback, useEffect, useState } from 'react'
 import { X } from 'lucide-react'
+import { useT } from '../i18n'
 
 function clampByte(n: number): number {
   return Math.min(255, Math.max(0, Math.round(n)))
@@ -40,6 +41,7 @@ export default function ColorPickerModal({
   onApply: (color: string) => void
   onClose: () => void
 }) {
+  const t = useT()
   const parsed = hexToRgb(initialColor) ?? { r: 8, g: 6, b: 13 }
   const [r, setR] = useState(parsed.r)
   const [g, setG] = useState(parsed.g)
@@ -91,11 +93,11 @@ export default function ColorPickerModal({
         onClick={(e) => e.stopPropagation()}
       >
         <div className="modal-header">
-          <h2 id="color-picker-modal-title">Custom color</h2>
+          <h2 id="color-picker-modal-title">{t('color.custom')}</h2>
           <button
             type="button"
             className="modal-close"
-            aria-label="Close"
+            aria-label={t('common.close')}
             onClick={onClose}
           >
             <X size={16} aria-hidden />
@@ -126,7 +128,7 @@ export default function ColorPickerModal({
                   value={value}
                   style={{ accentColor: accent }}
                   onChange={(e) => updateChannel(key, Number(e.target.value))}
-                  aria-label={`${label} channel`}
+                  aria-label={t('color.channel', { channel: label })}
                 />
                 <input
                   type="number"
@@ -135,20 +137,20 @@ export default function ColorPickerModal({
                   max={255}
                   value={value}
                   onChange={(e) => updateChannel(key, Number(e.target.value))}
-                  aria-label={`${label} value`}
+                  aria-label={t('color.channelValue', { channel: label })}
                 />
               </label>
             ))}
           </div>
 
           <label className="color-picker-hex">
-            <span className="color-picker-channel-label">Hex</span>
+            <span className="color-picker-channel-label">{t('color.hex')}</span>
             <input
               type="text"
               value={hexInput}
               spellCheck={false}
               onChange={(e) => applyHexInput(e.target.value)}
-              aria-label="Hex color"
+              aria-label={t('color.hexAria')}
             />
           </label>
         </div>
@@ -156,14 +158,14 @@ export default function ColorPickerModal({
         <div className="modal-actions modal-actions-split">
           <div className="modal-actions-group">
             <button type="button" className="button" onClick={onClose}>
-              Cancel
+              {t('common.cancel')}
             </button>
             <button
               type="button"
               className="button button-primary"
               onClick={handleApply}
             >
-              Apply
+              {t('common.apply')}
             </button>
           </div>
         </div>
diff --git a/src/components/EditGpxModal.tsx b/src/components/EditGpxModal.tsx
index 9ec5188..a51ae52 100644
--- a/src/components/EditGpxModal.tsx
+++ b/src/components/EditGpxModal.tsx
@@ -18,6 +18,7 @@ import type { LayoutMode } from '../hooks/useLayoutMode'
 import Tooltip from './Tooltip'
 import GpxCropPanel from './GpxCropPanel'
 import DualRangeSlider from './DualRangeSlider'
+import { useT } from '../i18n'
 
 const PACE_SLIDER_MIN = 2
 const PACE_SLIDER_MAX = 20
@@ -103,6 +104,7 @@ export default function EditGpxModal({
   onClose: () => void
   onUploadNew: () => void
 }) {
+  const t = useT()
   const tracks = useAppStore((s) => s.tracks)
   const mapImage = useAppStore((s) => s.mapImage)
   const updateTrack = useAppStore((s) => s.updateTrack)
@@ -129,7 +131,7 @@ export default function EditGpxModal({
     setActiveTool('gpx')
     onClose()
     if (isTouch) {
-      setToastMessage('Tap the track to add pins. Long-press a pin to delete.')
+      setToastMessage(t('gpx.toastTapHint'))
     }
   }
 
@@ -160,11 +162,11 @@ export default function EditGpxModal({
         onClick={(e) => e.stopPropagation()}
       >
         <div className="modal-header">
-          <h2 id="gpx-modal-title">GPX tracks</h2>
+          <h2 id="gpx-modal-title">{t('gpx.title')}</h2>
           <button
             type="button"
             className="modal-close"
-            aria-label="Close"
+            aria-label={t('common.close')}
             onClick={onClose}
           >
             <X size={16} aria-hidden />
@@ -330,7 +332,7 @@ export default function EditGpxModal({
                           onClick={() => toggleCrop(track.id)}
                         >
                           <Scissors size={14} aria-hidden />
-                          Crop
+                          {t('gpx.crop')}
                         </button>
                         <button
                           type="button"
@@ -338,7 +340,7 @@ export default function EditGpxModal({
                           onClick={adjustTrack}
                         >
                           <Anchor size={14} aria-hidden />
-                          Adjust on map
+                          {t('gpx.adjustMap')}
                         </button>
                         <button
                           type="button"
@@ -346,37 +348,37 @@ export default function EditGpxModal({
                           onClick={() => handleRemove(track.id)}
                         >
                           <Trash2 size={14} aria-hidden />
-                          Remove
+                          {t('gpx.remove')}
                         </button>
                       </>
                     ) : (
                       <>
-                        <Tooltip content="Crop start and end of track">
+                        <Tooltip content={t('gpx.tipCrop')}>
                           <button
                             type="button"
                             className={`button button-icon-only${isCropping ? ' active' : ''}`}
-                            aria-label="Crop track"
+                            aria-label={t('gpx.cropAria')}
                             aria-pressed={isCropping}
                             onClick={() => toggleCrop(track.id)}
                           >
                             <Scissors size={14} aria-hidden />
                           </button>
                         </Tooltip>
-                        <Tooltip content="Switch to map and drag anchor pins">
+                        <Tooltip content={t('gpx.tipAdjust')}>
                           <button
                             type="button"
                             className="button button-icon-only"
-                            aria-label="Adjust on map"
+                            aria-label={t('gpx.adjustMap')}
                             onClick={adjustTrack}
                           >
                             <Anchor size={14} aria-hidden />
                           </button>
                         </Tooltip>
-                        <Tooltip content="Remove this track from the project">
+                        <Tooltip content={t('gpx.tipRemove')}>
                           <button
                             type="button"
                             className="button button-icon-only modal-track-remove"
-                            aria-label="Remove track"
+                            aria-label={t('gpx.removeAria')}
                             onClick={() => handleRemove(track.id)}
                           >
                             <Trash2 size={14} aria-hidden />
@@ -393,7 +395,7 @@ export default function EditGpxModal({
                       <div
                         className="gpx-line-style-toggle"
                         role="group"
-                        aria-label="Line style"
+                        aria-label={t('gpx.lineStyleAria')}
                       >
                         <button
                           type="button"
@@ -403,7 +405,7 @@ export default function EditGpxModal({
                           aria-pressed={!paceMode && !hrMode}
                           onClick={() => setLineStyle('solid')}
                         >
-                          Solid
+                          {t('gpx.solid')}
                         </button>
                         {timing && (
                           <button
@@ -412,7 +414,7 @@ export default function EditGpxModal({
                             aria-pressed={paceMode}
                             onClick={() => setLineStyle('pace')}
                           >
-                            Pace
+                            {t('gpx.pace')}
                           </button>
                         )}
                         {hasHr && (
@@ -422,7 +424,7 @@ export default function EditGpxModal({
                             aria-pressed={hrMode}
                             onClick={() => setLineStyle('hr')}
                           >
-                            HR
+                            {t('gpx.hr')}
                           </button>
                         )}
                       </div>
@@ -434,19 +436,19 @@ export default function EditGpxModal({
                           type="button"
                           className={`swatch${track.color === color ? ' active' : ''}`}
                           style={{ background: color }}
-                          aria-label={`Track colour ${color}`}
+                          aria-label={t('gpx.trackColour', { color })}
                           onClick={() => updateTrack(track.id, { color })}
                         />
                       ))}
                     </div>
                     <label className="modal-track-slider">
-                      <span className="modal-track-slider-label">Width</span>
+                      <span className="modal-track-slider-label">{t('gpx.width')}</span>
                       <input
                         type="range"
                         min={minWidth}
                         max={maxWidth}
                         value={width}
-                        aria-label="Stroke width"
+                        aria-label={t('gpx.strokeWidth')}
                         onChange={(e) =>
                           updateTrack(
                             track.id,
@@ -459,13 +461,13 @@ export default function EditGpxModal({
                     </label>
                     <div className="modal-track-sliders-row">
                       <label className="modal-track-slider">
-                        <span className="modal-track-slider-label">Opac</span>
+                        <span className="modal-track-slider-label">{t('gpx.opacityShort')}</span>
                         <input
                           type="range"
                           min={10}
                           max={100}
                           value={opacity}
-                          aria-label="Opacity"
+                          aria-label={t('gpx.opacity')}
                           onChange={(e) =>
                             updateTrack(
                               track.id,
@@ -481,7 +483,7 @@ export default function EditGpxModal({
                           <i
                             className="modal-track-pace-swatch"
                             style={{ background: '#16a34a' }}
-                            title="Fast (green)"
+                            title={t('gpx.fast')}
                             aria-hidden
                           />
                           <ScaleValueInput
@@ -513,7 +515,7 @@ export default function EditGpxModal({
                           <i
                             className="modal-track-pace-swatch"
                             style={{ background: '#dc2626' }}
-                            title="Slow (red)"
+                            title={t('gpx.slow')}
                             aria-hidden
                           />
                         </div>
@@ -523,7 +525,7 @@ export default function EditGpxModal({
                           <i
                             className="modal-track-pace-swatch"
                             style={{ background: HR_LOW_COLOR }}
-                            title="Low HR (dark red)"
+                            title={t('gpx.lowHr')}
                             aria-hidden
                           />
                           <ScaleValueInput
@@ -555,7 +557,7 @@ export default function EditGpxModal({
                           <i
                             className="modal-track-pace-swatch"
                             style={{ background: HR_HIGH_COLOR }}
-                            title="High HR (bright red)"
+                            title={t('gpx.highHr')}
                             aria-hidden
                           />
                         </div>
@@ -578,7 +580,7 @@ export default function EditGpxModal({
             )
           })}
           {tracks.length === 0 && (
-            <li className="modal-empty">No GPX tracks loaded.</li>
+            <li className="modal-empty">{t('gpx.empty')}</li>
           )}
         </ul>
 
@@ -592,14 +594,14 @@ export default function EditGpxModal({
             }}
           >
             <Upload size={14} aria-hidden />
-            Upload
+            {t('gpx.upload')}
           </button>
           <button
             type="button"
             className="button button-primary"
             onClick={onClose}
           >
-            Confirm
+            {t('gpx.confirm')}
           </button>
         </div>
       </div>
diff --git a/src/components/ExportModal.tsx b/src/components/ExportModal.tsx
index a1292dc..0a475cb 100644
--- a/src/components/ExportModal.tsx
+++ b/src/components/ExportModal.tsx
@@ -14,6 +14,7 @@ import {
   type ExportPreviewImages,
 } from '../utils/export'
 import type { LayoutMode } from '../hooks/useLayoutMode'
+import { t, useT } from '../i18n'
 import { useEscapeKey } from '../hooks/useEscapeKey'
 
 const PREVIEW_ZOOM_MIN = 1
@@ -23,7 +24,7 @@ const PREVIEW_ZOOM_STEP = 0.25
 function exportFailureMessage(error: unknown): string {
   return error instanceof Error
     ? error.message
-    : 'Export failed — please try again'
+    : t('export.failed')
 }
 
 export default function ExportModal({
@@ -33,6 +34,7 @@ export default function ExportModal({
   layoutMode: LayoutMode
   onClose: () => void
 }) {
+  const t = useT()
   const annotations = useAppStore((s) => s.annotations)
   const markerDisplayMode = useAppStore((s) => s.markerDisplayMode)
 
@@ -228,7 +230,7 @@ export default function ExportModal({
 
   const zoomLabel =
     previewZoom <= 1.01
-      ? 'Fit'
+      ? t('export.fit')
       : useFullRes
         ? `${Math.round(Math.min(100, displayScale * 100))}%`
         : `${Math.round(previewZoom * 100)}%`
@@ -243,11 +245,11 @@ export default function ExportModal({
         onClick={(e) => e.stopPropagation()}
       >
         <div className="modal-header">
-          <h2 id="export-modal-title">Export</h2>
+          <h2 id="export-modal-title">{t('export.title')}</h2>
           <button
             type="button"
             className="modal-close"
-            aria-label="Close"
+            aria-label={t('common.close')}
             onClick={onClose}
           >
             <X size={16} aria-hidden />
@@ -260,12 +262,12 @@ export default function ExportModal({
             className={`export-preview-wrap${isPanning ? ' is-panning' : ''}${previewZoom > 1 ? ' is-zoomed' : ''}`}
           >
             {previewLoading && !previews && (
-              <p className="export-preview-placeholder">Generating preview…</p>
+              <p className="export-preview-placeholder">{t('export.generating')}</p>
             )}
             {previews && (
               <>
                 {!previewReady && (
-                  <p className="export-preview-placeholder">Loading preview…</p>
+                  <p className="export-preview-placeholder">{t('export.loadingPreview')}</p>
                 )}
                 <div
                   className="export-preview-stage"
@@ -293,7 +295,7 @@ export default function ExportModal({
                   />
                   <img
                     src={previews.full.url}
-                    alt="Export preview"
+                    alt={t('export.previewAlt')}
                     width={previews.full.width}
                     height={previews.full.height}
                     className={`export-preview-image export-preview-image-full${useFullRes ? '' : ' export-preview-image-hidden'}${previewLoading ? ' export-preview-image-loading' : ''}`}
@@ -309,7 +311,7 @@ export default function ExportModal({
                   <button
                     type="button"
                     className="button export-preview-zoom-btn"
-                    aria-label="Zoom out"
+                    aria-label={t('export.zoomOut')}
                     disabled={previewZoom <= PREVIEW_ZOOM_MIN + 0.01}
                     onClick={() =>
                       setZoom((current) => current - PREVIEW_ZOOM_STEP)
@@ -320,7 +322,7 @@ export default function ExportModal({
                   <button
                     type="button"
                     className="button export-preview-zoom-btn"
-                    aria-label="Zoom in"
+                    aria-label={t('export.zoomIn')}
                     disabled={previewZoom >= previewZoomMax - 0.01}
                     onClick={() =>
                       setZoom((current) => current + PREVIEW_ZOOM_STEP)
@@ -331,7 +333,7 @@ export default function ExportModal({
                   <button
                     type="button"
                     className="button export-preview-zoom-btn"
-                    aria-label="Reset zoom"
+                    aria-label={t('export.resetZoom')}
                     disabled={
                       previewZoom <= 1.01 &&
                       Math.abs(previewPan.x) < 1 &&
@@ -343,7 +345,7 @@ export default function ExportModal({
                   </button>
                 </div>
                 <p className="export-preview-hint">
-                  Scroll to zoom · drag to pan
+                  {t('export.hint')}
                 </p>
               </>
             )}
@@ -357,23 +359,23 @@ export default function ExportModal({
                   checked={includeSidebar}
                   onChange={(e) => setIncludeSidebar(e.target.checked)}
                 />
-                <span>Include annotation sidebar</span>
+                <span>{t('export.includeSidebar')}</span>
               </label>
               <p className="export-control-hint">
                 {markerDisplayMode === 'comments'
-                  ? 'Comments are shown on the map — turn off the sidebar to avoid duplicating them.'
-                  : 'The sidebar lists each marker letter with its comment.'}
+                  ? t('export.sidebarWithComments')
+                  : t('export.sidebarWithLabels')}
               </p>
 
               <label className="export-slider">
-                <span className="export-slider-label">Text size</span>
+                <span className="export-slider-label">{t('export.textSize')}</span>
                 <input
                   type="range"
                   min={ANNOTATION_TEXT_SCALE_MIN}
                   max={ANNOTATION_TEXT_SCALE_MAX}
                   step={ANNOTATION_TEXT_SCALE_STEP}
                   value={textScalePct}
-                  aria-label="Text size"
+                  aria-label={t('export.textSize')}
                   onChange={(e) =>
                     setAnnotationTextScalePct(Number(e.target.value))
                   }
@@ -391,14 +393,13 @@ export default function ExportModal({
         )}
         {!exportError && previews && previews.scale < 1 && (
           <p className="export-status" role="status">
-            This map is larger than this device can export at full size, so the
-            PNG will be {Math.round(previews.scale * 100)}% of native resolution.
+            {t('export.scaleNotice', { percent: Math.round(previews.scale * 100) })}
           </p>
         )}
 
         <div className={`modal-actions${isTouch ? ' modal-actions-touch' : ''}`}>
           <button type="button" className="button" onClick={onClose}>
-            Cancel
+            {t('common.cancel')}
           </button>
           <button
             type="button"
@@ -407,7 +408,7 @@ export default function ExportModal({
             onClick={() => void handleExport()}
           >
             <Download size={14} aria-hidden />
-            {exporting ? 'Exporting…' : 'Download PNG'}
+            {exporting ? t('export.exporting') : t('export.download')}
           </button>
         </div>
       </div>
diff --git a/src/components/GpxCropPanel.tsx b/src/components/GpxCropPanel.tsx
index d3d69e9..8695630 100644
--- a/src/components/GpxCropPanel.tsx
+++ b/src/components/GpxCropPanel.tsx
@@ -7,6 +7,7 @@ import {
   formatPace,
   vertexCount,
 } from '../utils/gpxMetrics'
+import { formatNumber, t, useT } from '../i18n'
 
 const CHART_HEIGHT = 160
 const PAD = { top: 14, right: 14, bottom: 30, left: 46 }
@@ -18,8 +19,8 @@ interface GpxCropPanelProps {
 }
 
 function formatDistanceKm(km: number): string {
-  if (km < 10) return `${km.toFixed(2)} km`
-  return `${km.toFixed(1)} km`
+  const digits = km < 10 ? 2 : 1
+  return t('gpx.km', { value: formatNumber(km, digits) })
 }
 
 export default function GpxCropPanel({
@@ -27,6 +28,7 @@ export default function GpxCropPanel({
   onApply,
   onCancel,
 }: GpxCropPanelProps) {
+  const t = useT()
   const n = vertexCount(track)
   const [startIndex, setStartIndex] = useState(0)
   const [endIndex, setEndIndex] = useState(n - 1)
@@ -155,10 +157,10 @@ export default function GpxCropPanel({
 
   return (
     <div className="gpx-crop-panel">
-      <p className="gpx-crop-panel-title">Crop track</p>
+      <p className="gpx-crop-panel-title">{t('gpx.cropTitle')}</p>
       {!hasTiming && (
         <p className="gpx-crop-panel-note">
-          No timing data in this GPX — crop by distance
+          {t('gpx.noTiming')}
         </p>
       )}
 
@@ -326,12 +328,12 @@ export default function GpxCropPanel({
       </div>
 
       {!isValid && (
-        <p className="gpx-crop-error">Selection must include at least 2 points.</p>
+        <p className="gpx-crop-error">{t('gpx.cropError')}</p>
       )}
 
       <div className="gpx-crop-actions">
         <button type="button" className="button button-small" onClick={onCancel}>
-          Cancel
+          {t('common.cancel')}
         </button>
         <button
           type="button"
@@ -339,7 +341,7 @@ export default function GpxCropPanel({
           disabled={!isValid || isUnchanged}
           onClick={() => onApply(cropTrack(track, startIndex, endIndex))}
         >
-          Apply crop
+          {t('gpx.applyCrop')}
         </button>
       </div>
     </div>
diff --git a/src/components/LanguageSelect.tsx b/src/components/LanguageSelect.tsx
new file mode 100644
index 0000000..9228f90
--- /dev/null
+++ b/src/components/LanguageSelect.tsx
@@ -0,0 +1,22 @@
+import { LOCALES, getLocale, setLocale, useT, type Locale } from '../i18n'
+
+/** Language picker. Switching takes effect immediately; the choice is remembered. */
+export default function LanguageSelect({ className = 'statusbar-language' }: { className?: string }) {
+  const t = useT()
+
+  return (
+    <select
+      className={className}
+      value={getLocale()}
+      aria-label={t('language.label')}
+      title={t('language.label')}
+      onChange={(e) => void setLocale(e.target.value as Locale)}
+    >
+      {LOCALES.map(({ code, name }) => (
+        <option key={code} value={code} lang={code}>
+          {name}
+        </option>
+      ))}
+    </select>
+  )
+}
diff --git a/src/components/LegalModal.tsx b/src/components/LegalModal.tsx
index fb55b80..b11a1ad 100644
--- a/src/components/LegalModal.tsx
+++ b/src/components/LegalModal.tsx
@@ -1,6 +1,7 @@
 import { X } from 'lucide-react'
 import { LEGAL_DOCUMENTS, type LegalDocumentId } from '../content/legal'
 import Portal from './Portal'
+import { useT } from '../i18n'
 import { useEscapeKey } from '../hooks/useEscapeKey'
 
 export default function LegalModal({
@@ -10,6 +11,7 @@ export default function LegalModal({
   documentId: LegalDocumentId
   onClose: () => void
 }) {
+  const t = useT()
   const doc = LEGAL_DOCUMENTS[documentId]
 
   useEscapeKey(onClose)
@@ -29,14 +31,15 @@ export default function LegalModal({
             <button
               type="button"
               className="modal-close"
-              aria-label="Close"
+              aria-label={t('common.close')}
               onClick={onClose}
             >
               <X size={16} aria-hidden />
             </button>
           </div>
           <div className="modal-body legal-body">
-            <p className="legal-updated">Last updated: {doc.updated}</p>
+            <p className="legal-updated">{t('legal.lastUpdated', { date: doc.updated })}</p>
+            <p className="legal-binding">{t('legal.binding')}</p>
             {doc.sections.map((section) => (
               <section key={section.heading} className="legal-section">
                 <h3>{section.heading}</h3>
diff --git a/src/components/ProjectLibraryModal.tsx b/src/components/ProjectLibraryModal.tsx
index e978f80..cef2ec9 100644
--- a/src/components/ProjectLibraryModal.tsx
+++ b/src/components/ProjectLibraryModal.tsx
@@ -5,6 +5,7 @@ import { useEscapeKey } from '../hooks/useEscapeKey'
 import type { LayoutMode } from '../hooks/useLayoutMode'
 import {
   listProjectMetas,
+  projectDisplayName,
   readThumbnail,
   type ProjectMeta,
 } from '../persistence/library'
@@ -16,6 +17,7 @@ import {
   renameLibraryProject,
 } from '../projectLibrary'
 import { useSaveState } from '../saveStatus'
+import { getLocale, useT } from '../i18n'
 
 export default function ProjectLibraryModal({
   layoutMode,
@@ -24,6 +26,7 @@ export default function ProjectLibraryModal({
   layoutMode: LayoutMode
   onClose: () => void
 }) {
+  const t = useT()
   const currentId = useAppStore((s) => s.projectId)
   const saveState = useSaveState()
   const [metas, setMetas] = useState<ProjectMeta[] | null>(null)
@@ -80,7 +83,7 @@ export default function ProjectLibraryModal({
     try {
       await action()
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Something went wrong')
+      setError(err instanceof Error ? err.message : t('common.errorGeneric'))
     } finally {
       setBusy(false)
     }
@@ -131,11 +134,11 @@ export default function ProjectLibraryModal({
         onClick={(e) => e.stopPropagation()}
       >
         <div className="modal-header">
-          <h2 id="project-library-title">Projects</h2>
+          <h2 id="project-library-title">{t('library.title')}</h2>
           <button
             type="button"
             className="modal-close"
-            aria-label="Close"
+            aria-label={t('common.close')}
             onClick={onClose}
           >
             <X size={16} aria-hidden />
@@ -149,11 +152,11 @@ export default function ProjectLibraryModal({
             </p>
           )}
 
-          {metas === null && <p className="project-library-empty">Loading…</p>}
+          {metas === null && <p className="project-library-empty">{t('common.loading')}</p>}
 
           {metas?.length === 0 && (
             <p className="project-library-empty">
-              No saved projects yet. Import a map to start one.
+              {t('library.empty')}
             </p>
           )}
 
@@ -181,7 +184,7 @@ export default function ProjectLibraryModal({
                           autoFocus
                           value={draftName}
                           maxLength={80}
-                          aria-label="Project name"
+                          aria-label={t('top.projectName')}
                           onChange={(e) => setDraftName(e.target.value)}
                           onBlur={() => void commitRename(meta)}
                           onKeyDown={(e) => {
@@ -206,16 +209,18 @@ export default function ProjectLibraryModal({
                         </span>
                         <span className="project-library-text">
                           <span className="project-library-name">
-                            {meta.name}
+                            {projectDisplayName(meta.name)}
                             {isCurrent && (
-                              <span className="project-library-badge">Open</span>
+                              <span className="project-library-badge">{t('library.open')}</span>
                             )}
                           </span>
                           <span className="project-library-meta">
-                            {meta.mapName ?? 'No map yet'} · Updated{' '}
-                            {new Date(meta.updatedAt).toLocaleString([], {
-                              dateStyle: 'medium',
-                              timeStyle: 'short',
+                            {t('library.updated', {
+                              map: meta.mapName ?? t('library.noMap'),
+                              date: new Date(meta.updatedAt).toLocaleString(getLocale(), {
+                                dateStyle: 'medium',
+                                timeStyle: 'short',
+                              }),
                             })}
                           </span>
                         </span>
@@ -230,7 +235,7 @@ export default function ProjectLibraryModal({
                             className="button"
                             onClick={() => setConfirmDeleteId(null)}
                           >
-                            Cancel
+                            {t('common.cancel')}
                           </button>
                           <button
                             type="button"
@@ -238,7 +243,7 @@ export default function ProjectLibraryModal({
                             disabled={busy}
                             onClick={() => remove(meta)}
                           >
-                            Delete
+                            {t('common.delete')}
                           </button>
                         </>
                       ) : (
@@ -246,8 +251,8 @@ export default function ProjectLibraryModal({
                           <button
                             type="button"
                             className="button button-icon-only"
-                            aria-label={`Rename ${meta.name}`}
-                            title="Rename"
+                            aria-label={t('library.renameAria', { name: meta.name })}
+                            title={t('common.rename')}
                             disabled={busy || isEditing}
                             onClick={() => {
                               setEditingId(meta.id)
@@ -259,8 +264,8 @@ export default function ProjectLibraryModal({
                           <button
                             type="button"
                             className="button button-icon-only"
-                            aria-label={`Delete ${meta.name}`}
-                            title="Delete"
+                            aria-label={t('library.deleteAria', { name: meta.name })}
+                            title={t('common.delete')}
                             disabled={busy}
                             onClick={() => remove(meta)}
                           >
@@ -278,7 +283,7 @@ export default function ProjectLibraryModal({
 
         <div className="modal-actions">
           <button type="button" className="button" onClick={onClose}>
-            Close
+            {t('common.close')}
           </button>
           <button
             type="button"
@@ -287,7 +292,7 @@ export default function ProjectLibraryModal({
             onClick={() => void startNew()}
           >
             <FilePlus size={14} aria-hidden />
-            New project
+            {t('action.newProject')}
           </button>
         </div>
       </div>
diff --git a/src/components/PwaUpdateBanner.tsx b/src/components/PwaUpdateBanner.tsx
index 37e90bb..edee56e 100644
--- a/src/components/PwaUpdateBanner.tsx
+++ b/src/components/PwaUpdateBanner.tsx
@@ -1,7 +1,9 @@
 import { RefreshCw, X } from 'lucide-react'
 import { usePwaUpdate } from '../hooks/usePwaUpdate'
+import { useT } from '../i18n'
 
 export default function PwaUpdateBanner() {
+  const t = useT()
   const { updateAvailable, applyUpdate, dismissUpdate } = usePwaUpdate()
 
   if (!updateAvailable) return null
@@ -9,18 +11,18 @@ export default function PwaUpdateBanner() {
   return (
     <div className="pwa-update-banner" role="alert">
       <RefreshCw size={16} aria-hidden />
-      <span>A new version of O-Analysis is available.</span>
+      <span>{t('pwa.updateAvailable')}</span>
       <button
         type="button"
         className="button button-primary pwa-update-banner-action"
         onClick={applyUpdate}
       >
-        Update now
+        {t('pwa.updateNow')}
       </button>
       <button
         type="button"
         className="pwa-update-banner-dismiss"
-        aria-label="Dismiss update notice"
+        aria-label={t('pwa.dismissUpdate')}
         onClick={dismissUpdate}
       >
         <X size={14} aria-hidden />
diff --git a/src/components/SlideDrawer.tsx b/src/components/SlideDrawer.tsx
index f57ac4e..0ffd336 100644
--- a/src/components/SlideDrawer.tsx
+++ b/src/components/SlideDrawer.tsx
@@ -1,5 +1,6 @@
 import { useEffect } from 'react'
 import { X } from 'lucide-react'
+import { useT } from '../i18n'
 
 export default function SlideDrawer({
   title,
@@ -12,6 +13,7 @@ export default function SlideDrawer({
   onClose: () => void
   children: React.ReactNode
 }) {
+  const t = useT()
   useEffect(() => {
     if (!open) return
     const onKeyDown = (e: KeyboardEvent) => {
@@ -38,7 +40,7 @@ export default function SlideDrawer({
             <button
               type="button"
               className="slide-drawer-close"
-              aria-label="Close"
+              aria-label={t('common.close')}
               onClick={onClose}
             >
               <X size={16} aria-hidden />
diff --git a/src/components/StatusBar.tsx b/src/components/StatusBar.tsx
index e0053d7..d7bef7b 100644
--- a/src/components/StatusBar.tsx
+++ b/src/components/StatusBar.tsx
@@ -8,6 +8,8 @@ import type { SaveStatus } from '../saveStatus'
 import { stageRef } from '../stageRef'
 import { useSaveState } from '../saveStatus'
 import TextSizeSlider from './TextSizeSlider'
+import LanguageSelect from './LanguageSelect'
+import { getLocale, useT } from '../i18n'
 import CanvasRotationControl from './CanvasRotationControl'
 import LegalModal from './LegalModal'
 
@@ -20,16 +22,17 @@ function SaveIndicator({
 }: {
   state: { status: SaveStatus; savedAt: number | null }
 }) {
+  const t = useT()
   if (state.status === 'idle') return null
   const label =
     state.status === 'error'
-      ? 'Autosave failed'
+      ? t('save.failed')
       : state.status === 'saved' && state.savedAt
-        ? `Saved ${new Date(state.savedAt).toLocaleTimeString([], {
+        ? t('save.saved', { time: new Date(state.savedAt).toLocaleTimeString(getLocale(), {
             hour: '2-digit',
             minute: '2-digit',
-          })}`
-        : 'Saving…'
+          }) })
+        : t('save.saving')
   return (
     <span
       className={`statusbar-save${state.status === 'error' ? ' statusbar-save-error' : ''}`}
@@ -46,6 +49,7 @@ export default function StatusBar({
 }: {
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const activeTool = useAppStore((s) => s.activeTool)
   const scale = useAppStore((s) => s.viewport.scale)
   const setViewport = useAppStore((s) => s.setViewport)
@@ -90,8 +94,8 @@ export default function StatusBar({
         className="statusbar-zoom"
         disabled={!hasMap}
         onClick={requestFitToView}
-        title="Fit the map to the screen"
-        aria-label={`Zoom ${Math.round(scale * 100)}%. Fit map to screen`}
+        title={t('status.fitHint')}
+        aria-label={t('status.fitAria', { zoom: Math.round(scale * 100) })}
       >
         <Maximize2 size={12} aria-hidden />
         <span>{Math.round(scale * 100)}%</span>
@@ -102,7 +106,7 @@ export default function StatusBar({
           <button
             type="button"
             className="statusbar-zoom-btn"
-            aria-label="Zoom out"
+            aria-label={t('status.zoomOut')}
             onClick={() => zoomBy(-1)}
           >
             <Minus size={14} aria-hidden />
@@ -110,33 +114,34 @@ export default function StatusBar({
           <button
             type="button"
             className="statusbar-zoom-btn"
-            aria-label="Zoom in"
+            aria-label={t('status.zoomIn')}
             onClick={() => zoomBy(1)}
           >
             <Plus size={14} aria-hidden />
           </button>
         </span>
       )}
-      {showTextSize && <TextSizeSlider label={layoutMode === 'compact' ? 'Text' : 'Text Size'} />}
+      {showTextSize && <TextSizeSlider label={layoutMode === 'compact' ? t('status.textSizeShort') : t('status.textSize')} />}
       {showCoords && (
         <span>
           {pointer
-            ? `X: ${Math.round(pointer.x)} Y: ${Math.round(pointer.y)}`
-            : 'X: — Y: —'}
+            ? t('status.coords', { x: Math.round(pointer.x), y: Math.round(pointer.y) })
+            : t('status.noCoords')}
         </span>
       )}
       {showToolName && (
-        <span className="statusbar-tool">Tool: {getToolLabel(activeTool)}</span>
+        <span className="statusbar-tool">{t('status.tool', { tool: getToolLabel(activeTool) })}</span>
       )}
       <SaveIndicator state={saveState} />
+      {showLegalLinks && <LanguageSelect />}
       {showLegalLinks && (
-        <nav className="statusbar-legal" aria-label="Legal">
+        <nav className="statusbar-legal" aria-label={t('status.legal')}>
           <button
             type="button"
             className="statusbar-legal-link"
             onClick={() => setLegalDoc('privacy')}
           >
-            Privacy
+            {t('status.privacy')}
           </button>
           <span className="statusbar-legal-sep" aria-hidden>
             ·
@@ -146,7 +151,7 @@ export default function StatusBar({
             className="statusbar-legal-link"
             onClick={() => setLegalDoc('terms')}
           >
-            Terms
+            {t('status.terms')}
           </button>
            {showCredit && (
             <>
@@ -159,7 +164,7 @@ export default function StatusBar({
                 target="_blank"
                 rel="noopener noreferrer"
               >
-                by Anthony Riley ❤️
+                {t('status.credit')}
               </a>
             </>
           )}
diff --git a/src/components/StrokeSettings.tsx b/src/components/StrokeSettings.tsx
index ee05aa0..c359e71 100644
--- a/src/components/StrokeSettings.tsx
+++ b/src/components/StrokeSettings.tsx
@@ -4,6 +4,7 @@ import { useAppStore } from '../store'
 import ColorPickerModal from './ColorPickerModal'
 import Tooltip from './Tooltip'
 import type { LayoutMode } from '../hooks/useLayoutMode'
+import { useT } from '../i18n'
 
 const DEFAULT_CUSTOM_COLOR = '#08060d'
 
@@ -12,6 +13,7 @@ export default function StrokeSettings({
 }: {
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const strokeWidth = useAppStore((s) => s.strokeWidth)
   const setStrokeWidth = useAppStore((s) => s.setStrokeWidth)
   const strokeColor = useAppStore((s) => s.strokeColor)
@@ -37,7 +39,7 @@ export default function StrokeSettings({
     <button
       type="button"
       className={`swatch swatch-custom${isCustomActive ? ' active' : ''}`}
-      aria-label="Custom color"
+      aria-label={t('stroke.custom')}
       aria-pressed={isCustomActive}
       onClick={() => setPickerOpen(true)}
     >
@@ -61,7 +63,7 @@ export default function StrokeSettings({
       <div className="stroke-settings-touch">
         <div className="tool-section tool-section-horizontal">
           <label className="tool-label" htmlFor="stroke-width">
-            Width
+            {t('stroke.width')}
           </label>
           <input
             id="stroke-width"
@@ -75,7 +77,7 @@ export default function StrokeSettings({
         </div>
         <div className="tool-section tool-section-horizontal">
           <label className="tool-label" htmlFor="stroke-opacity">
-            Opacity
+            {t('stroke.opacity')}
           </label>
           <input
             id="stroke-opacity"
@@ -88,7 +90,7 @@ export default function StrokeSettings({
           <span className="tool-value">{Math.round(strokeOpacity * 100)}%</span>
         </div>
         <div className="tool-section tool-section-horizontal">
-          <span className="tool-label">Color</span>
+          <span className="tool-label">{t('stroke.color')}</span>
           <div className="swatches swatches-row">
             {SWATCHES.map((color) => (
               <button
@@ -96,7 +98,7 @@ export default function StrokeSettings({
                 type="button"
                 className={`swatch${strokeColor === color ? ' active' : ''}`}
                 style={{ background: color }}
-                aria-label={`Color ${color}`}
+                aria-label={t('stroke.colorAria', { color })}
                 onClick={() => setStrokeColor(color)}
               />
             ))}
@@ -110,10 +112,10 @@ export default function StrokeSettings({
 
   return (
     <>
-      <Tooltip content="Line and marker stroke width" side="right">
+      <Tooltip content={t('stroke.widthHint')} side="right">
         <div className="tool-section">
           <label className="tool-label" htmlFor="stroke-width">
-            Width
+            {t('stroke.width')}
           </label>
           <input
             id="stroke-width"
@@ -126,10 +128,10 @@ export default function StrokeSettings({
           <span className="tool-value">{strokeWidth}px</span>
         </div>
       </Tooltip>
-      <Tooltip content="Transparency for drawn lines and markers" side="right">
+      <Tooltip content={t('stroke.opacityHint')} side="right">
         <div className="tool-section">
           <label className="tool-label" htmlFor="stroke-opacity">
-            Opacity
+            {t('stroke.opacity')}
           </label>
           <input
             id="stroke-opacity"
@@ -143,20 +145,20 @@ export default function StrokeSettings({
         </div>
       </Tooltip>
       <div className="tool-section">
-        <span className="tool-label">Color</span>
+        <span className="tool-label">{t('stroke.color')}</span>
         <div className="swatches">
           {SWATCHES.map((color) => (
-            <Tooltip key={color} content={`Use ${color}`} side="right">
+            <Tooltip key={color} content={t('stroke.useColor', { color })} side="right">
               <button
                 type="button"
                 className={`swatch${strokeColor === color ? ' active' : ''}`}
                 style={{ background: color }}
-                aria-label={`Color ${color}`}
+                aria-label={t('stroke.colorAria', { color })}
                 onClick={() => setStrokeColor(color)}
               />
             </Tooltip>
           ))}
-          <Tooltip content="Pick a custom color" side="right">
+          <Tooltip content={t('stroke.customHint')} side="right">
             {customSwatch}
           </Tooltip>
         </div>
diff --git a/src/components/ToastBanner.tsx b/src/components/ToastBanner.tsx
index c2a8f58..78840b2 100644
--- a/src/components/ToastBanner.tsx
+++ b/src/components/ToastBanner.tsx
@@ -1,8 +1,10 @@
 import { useEffect } from 'react'
 import { X } from 'lucide-react'
 import { useAppStore } from '../store'
+import { useT } from '../i18n'
 
 export default function ToastBanner() {
+  const t = useT()
   const message = useAppStore((s) => s.toastMessage)
   const setToastMessage = useAppStore((s) => s.setToastMessage)
 
@@ -20,7 +22,7 @@ export default function ToastBanner() {
       <button
         type="button"
         className="toast-banner-dismiss"
-        aria-label="Dismiss"
+        aria-label={t('common.dismiss')}
         onClick={() => setToastMessage(null)}
       >
         <X size={14} aria-hidden />
diff --git a/src/components/ToolPalette.tsx b/src/components/ToolPalette.tsx
index c64c510..6b50e87 100644
--- a/src/components/ToolPalette.tsx
+++ b/src/components/ToolPalette.tsx
@@ -1,5 +1,6 @@
 import { useEffect } from 'react'
 import { TOOLS, getToolByHotkey, getToolTip } from '../config/tools'
+import { useT } from '../i18n'
 import type { LayoutMode } from '../hooks/useLayoutMode'
 import { useAppStore } from '../store'
 import StrokeSettings from './StrokeSettings'
@@ -13,6 +14,7 @@ export default function ToolPalette({
   const activeTool = useAppStore((s) => s.activeTool)
   const setActiveTool = useAppStore((s) => s.setActiveTool)
   const hasTracks = useAppStore((s) => s.tracks.length > 0)
+  const t = useT()
 
   useEffect(() => {
     const onKeyDown = (e: KeyboardEvent) => {
@@ -43,19 +45,19 @@ export default function ToolPalette({
 
   return (
     <aside className="tool-palette">
-      <div className="tool-buttons" role="toolbar" aria-label="Drawing tools">
+      <div className="tool-buttons" role="toolbar" aria-label={t('toolbar.drawingTools')}>
         {TOOLS.map(({ id, label, hotkey, icon: Icon }) => {
           const tip =
             id === 'gpx' && !hasTracks
-              ? 'Import a GPX file first'
-              : `${getToolTip(id, layoutMode)} (${hotkey})`
+              ? t('tool.gpxNeedsFile')
+              : t('tool.hotkeyLabel', { tip: getToolTip(id, layoutMode), key: hotkey })
 
           return (
             <Tooltip key={id} content={tip} side="right">
               <button
                 type="button"
                 className={`tool-button${activeTool === id ? ' active' : ''}`}
-                aria-label={label}
+                aria-label={t(label)}
                 aria-keyshortcuts={hotkey}
                 aria-pressed={activeTool === id}
                 disabled={id === 'gpx' && !hasTracks}
diff --git a/src/components/TopBar.tsx b/src/components/TopBar.tsx
index 13d5d36..4985353 100644
--- a/src/components/TopBar.tsx
+++ b/src/components/TopBar.tsx
@@ -18,6 +18,7 @@ import { useAppStore } from '../store'
 import { importGpxFile, importImageFile } from '../utils/files'
 import { openProjectFile, saveProjectFile, PROJECT_FILE_EXTENSION } from '../utils/project'
 import { createProject, renameCurrentProject } from '../projectLibrary'
+import { projectDisplayName } from '../persistence/library'
 import ProjectLibraryModal from './ProjectLibraryModal'
 import { usePwaInstall } from '../hooks/usePwaInstall'
 import { usePwaUpdate } from '../hooks/usePwaUpdate'
@@ -27,12 +28,14 @@ import ExportModal from './ExportModal'
 import Tooltip from './Tooltip'
 import TopBarMenu from './TopBarMenu'
 import { buildOverflowActions } from './overflowActions'
+import { useT } from '../i18n'
 
 export default function TopBar({
   layoutMode,
 }: {
   layoutMode: LayoutMode
 }) {
+  const t = useT()
   const mapImage = useAppStore((s) => s.mapImage)
   const hasTracks = useAppStore((s) => s.tracks.length > 0)
   const hasPaths = useAppStore((s) => s.paths.length > 0)
@@ -91,7 +94,7 @@ export default function TopBar({
       <button
         type="button"
         className="topbar-error-dismiss"
-        aria-label="Dismiss error"
+        aria-label={t('top.dismissError')}
         onClick={() => setImportError(null)}
       >
         <X size={14} aria-hidden />
@@ -114,10 +117,10 @@ export default function TopBar({
           <input
             className="topbar-project-name"
             type="text"
-            value={projectName}
+            value={projectDisplayName(projectName)}
             maxLength={80}
-            aria-label="Project name"
-            title="Project name"
+            aria-label={t('top.projectName')}
+            title={t('top.projectName')}
             onChange={(e) => setProjectName(e.target.value)}
             onBlur={(e) => renameCurrentProject(e.target.value)}
           />
@@ -161,24 +164,24 @@ export default function TopBar({
           }}
         />
 
-        <div className="topbar-history" role="group" aria-label="History">
-          <Tooltip content="Undo last action (⌘Z / Ctrl+Z)">
+        <div className="topbar-history" role="group" aria-label={t('top.history')}>
+          <Tooltip content={t('top.undoHint')}>
             <button
               type="button"
               className="button button-icon-only"
               disabled={!canUndo}
-              aria-label="Undo"
+              aria-label={t('top.undo')}
               onClick={undo}
             >
               <Undo2 size={16} aria-hidden />
             </button>
           </Tooltip>
-          <Tooltip content="Redo (⌘⇧Z / Ctrl+Shift+Z)">
+          <Tooltip content={t('top.redoHint')}>
             <button
               type="button"
               className="button button-icon-only"
               disabled={!canRedo}
-              aria-label="Redo"
+              aria-label={t('top.redo')}
               onClick={redo}
             >
               <Redo2 size={16} aria-hidden />
@@ -191,8 +194,8 @@ export default function TopBar({
             <Tooltip
               content={
                 mapImage
-                  ? 'Replace the current map image'
-                  : 'Upload a map image — PNG, JPG, or drop a file on the canvas'
+                  ? t('top.replaceImageHint')
+                  : t('top.importImageHint')
               }
             >
               <button
@@ -202,15 +205,15 @@ export default function TopBar({
               >
                 <Image size={16} aria-hidden />
                 <span className="button-label">
-                  {mapImage ? 'Edit Image' : 'Import Image'}
+                  {mapImage ? t('action.editImage') : t('action.importImage')}
                 </span>
               </button>
             </Tooltip>
             <Tooltip
               content={
                 hasTracks
-                  ? 'Change track colours, width, or alignment'
-                  : 'Import a GPX file to overlay a route on the map'
+                  ? t('top.editGpxHint')
+                  : t('top.importGpxHint')
               }
             >
               <button
@@ -223,41 +226,41 @@ export default function TopBar({
               >
                 <Route size={16} aria-hidden />
                 <span className="button-label">
-                  {hasTracks ? 'Edit GPX' : 'Import GPX'}
+                  {hasTracks ? t('action.editGpx') : t('action.importGpx')}
                 </span>
               </button>
             </Tooltip>
-            <Tooltip content="Clear the canvas and start fresh">
+            <Tooltip content={t('top.newHint')}>
               <button type="button" className="button" onClick={handleNewProject}>
                 <FilePlus size={16} aria-hidden />
-                <span className="button-label">New</span>
+                <span className="button-label">{t('top.new')}</span>
               </button>
             </Tooltip>
-            <Tooltip content="Switch between saved projects">
+            <Tooltip content={t('top.projectsHint')}>
               <button
                 type="button"
                 className="button"
                 onClick={() => setLibraryOpen(true)}
               >
                 <Library size={16} aria-hidden />
-                <span className="button-label">Projects</span>
+                <span className="button-label">{t('top.projects')}</span>
               </button>
             </Tooltip>
-            <Tooltip content={`Open a saved project (${PROJECT_FILE_EXTENSION})`}>
+            <Tooltip content={t('top.openHint', { ext: PROJECT_FILE_EXTENSION })}>
               <button
                 type="button"
                 className="button"
                 onClick={() => projectInputRef.current?.click()}
               >
                 <FolderOpen size={16} aria-hidden />
-                <span className="button-label">Open</span>
+                <span className="button-label">{t('top.open')}</span>
               </button>
             </Tooltip>
             <Tooltip
               content={
                 canSave
-                  ? `Save your project as ${PROJECT_FILE_EXTENSION}`
-                  : 'Nothing to save yet — import a map or add annotations first'
+                  ? t('top.saveHint', { ext: PROJECT_FILE_EXTENSION })
+                  : t('top.saveDisabled')
               }
             >
               <button
@@ -267,14 +270,14 @@ export default function TopBar({
                 onClick={saveProjectFile}
               >
                 <Save size={16} aria-hidden />
-                <span className="button-label">Save</span>
+                <span className="button-label">{t('top.save')}</span>
               </button>
             </Tooltip>
             <Tooltip
               content={
                 mapImage
-                  ? 'Preview and download the map with drawings and annotations'
-                  : 'Import a map image before exporting'
+                  ? t('top.exportHint')
+                  : t('top.exportDisabled')
               }
             >
               <button
@@ -284,30 +287,30 @@ export default function TopBar({
                 onClick={() => setExportModalOpen(true)}
               >
                 <Download size={16} aria-hidden />
-                <span className="button-label">Export</span>
+                <span className="button-label">{t('action.export')}</span>
               </button>
             </Tooltip>
             {updateAvailable && (
-              <Tooltip content="Reload to use the latest version">
+              <Tooltip content={t('top.updateHint')}>
                 <button
                   type="button"
                   className="button button-primary"
                   onClick={applyUpdate}
                 >
                   <RefreshCw size={16} aria-hidden />
-                  <span className="button-label">Update App</span>
+                  <span className="button-label">{t('top.updateApp')}</span>
                 </button>
               </Tooltip>
             )}
             {canInstall && (
-              <Tooltip content="Install O-Analysis as a desktop app">
+              <Tooltip content={t('top.installHint')}>
                 <button
                   type="button"
                   className="button"
                   onClick={() => void install()}
                 >
                   <HardDriveDownload size={16} aria-hidden />
-                  <span className="button-label">Install App</span>
+                  <span className="button-label">{t('top.installApp')}</span>
                 </button>
               </Tooltip>
             )}
diff --git a/src/components/TopBarMenu.tsx b/src/components/TopBarMenu.tsx
index 6a963ea..fdb3ae1 100644
--- a/src/components/TopBarMenu.tsx
+++ b/src/components/TopBarMenu.tsx
@@ -4,6 +4,7 @@ import type { LegalDocumentId } from '../content/legal'
 import type { LayoutMode } from '../hooks/useLayoutMode'
 import BottomSheet from './BottomSheet'
 import LegalModal from './LegalModal'
+import { useT } from '../i18n'
 import type { TopBarMenuAction } from './overflowActions'
 
 export default function TopBarMenu({
@@ -15,6 +16,7 @@ export default function TopBarMenu({
 }) {
   const [open, setOpen] = useState(false)
   const [legalDoc, setLegalDoc] = useState<LegalDocumentId | null>(null)
+  const t = useT()
   const dropdownRef = useRef<HTMLDivElement>(null)
 
   const visibleActions = actions.filter((a) => !a.hidden)
@@ -33,7 +35,7 @@ export default function TopBarMenu({
           onClick={() => openLegal('privacy')}
         >
           <Shield size={16} aria-hidden />
-          <span>Privacy Policy</span>
+          <span>{t('menu.privacy')}</span>
         </button>
       </li>
       <li>
@@ -43,7 +45,7 @@ export default function TopBarMenu({
           onClick={() => openLegal('terms')}
         >
           <FileText size={16} aria-hidden />
-          <span>Terms of Service</span>
+          <span>{t('menu.terms')}</span>
         </button>
       </li>
     </ul>
@@ -90,21 +92,21 @@ export default function TopBarMenu({
         <button
           type="button"
           className="button button-icon-only"
-          aria-label="Menu"
+          aria-label={t('menu.menu')}
           aria-expanded={open}
           onClick={() => setOpen(true)}
         >
           <Menu size={18} aria-hidden />
         </button>
         {open && (
-          <BottomSheet title="Menu" onClose={() => setOpen(false)}>
+          <BottomSheet title={t('menu.menu')} onClose={() => setOpen(false)}>
             <div className="topbar-menu-sections">
               <div className="topbar-menu-section">
-                <h3>File</h3>
+                <h3>{t('menu.file')}</h3>
                 {menuItems}
               </div>
               <div className="topbar-menu-section">
-                <h3>Legal</h3>
+                <h3>{t('menu.legal')}</h3>
                 {legalMenuItems}
               </div>
             </div>
@@ -122,7 +124,7 @@ export default function TopBarMenu({
       <button
         type="button"
         className="button button-icon-only"
-        aria-label="More actions"
+        aria-label={t('menu.more')}
         aria-expanded={open}
         onClick={() => setOpen((v) => !v)}
       >
diff --git a/src/components/TouchHints.tsx b/src/components/TouchHints.tsx
index 0a56881..d2e7c3d 100644
--- a/src/components/TouchHints.tsx
+++ b/src/components/TouchHints.tsx
@@ -1,11 +1,13 @@
 import { useEffect, useState } from 'react'
 import { X } from 'lucide-react'
 import { useIsTouchLayout } from '../hooks/useLayoutMode'
+import { useT } from '../i18n'
 
 const STORAGE_KEY = 'touch-hints-dismissed'
 const AUTO_HIDE_MS = 12000
 
 export default function TouchHints() {
+  const t = useT()
   const isTouch = useIsTouchLayout()
   const [visible, setVisible] = useState(false)
 
@@ -30,14 +32,11 @@ export default function TouchHints() {
 
   return (
     <div className="touch-hints" role="status">
-      <p>
-        Pinch to zoom, use two fingers to pan. Tap a tool, then tap the map to
-        draw or place markers.
-      </p>
+      <p>{t('touch.tips')}</p>
       <button
         type="button"
         className="touch-hints-dismiss"
-        aria-label="Dismiss tips"
+        aria-label={t('touch.dismissTips')}
         onClick={dismiss}
       >
         <X size={14} aria-hidden />
diff --git a/src/components/overflowActions.tsx b/src/components/overflowActions.tsx
index d54fe34..0be4632 100644
--- a/src/components/overflowActions.tsx
+++ b/src/components/overflowActions.tsx
@@ -1,3 +1,4 @@
+import { t } from '../i18n'
 import {
   Download,
   FilePlus,
@@ -40,7 +41,7 @@ export function buildOverflowActions(opts: {
   return [
     {
       id: 'update',
-      label: 'Update App',
+      label: t('action.updateApp'),
       icon: <RefreshCw size={16} aria-hidden />,
       onClick: opts.onUpdate,
       primary: true,
@@ -48,44 +49,44 @@ export function buildOverflowActions(opts: {
     },
     {
       id: 'import-image',
-      label: opts.mapImage ? 'Edit Image' : 'Import Image',
+      label: opts.mapImage ? t('action.editImage') : t('action.importImage'),
       icon: <Image size={16} aria-hidden />,
       onClick: opts.onImportImage,
     },
     {
       id: 'import-gpx',
-      label: opts.hasTracks ? 'Edit GPX' : 'Import GPX',
+      label: opts.hasTracks ? t('action.editGpx') : t('action.importGpx'),
       icon: <Route size={16} aria-hidden />,
       onClick: opts.hasTracks ? opts.onEditGpx : opts.onImportGpx,
     },
     {
       id: 'new',
-      label: 'New Project',
+      label: t('action.newProject'),
       icon: <FilePlus size={16} aria-hidden />,
       onClick: opts.onNew,
     },
     {
       id: 'projects',
-      label: 'Projects',
+      label: t('action.projects'),
       icon: <Library size={16} aria-hidden />,
       onClick: opts.onProjects,
     },
     {
       id: 'open',
-      label: 'Open Project',
+      label: t('action.openProject'),
       icon: <FolderOpen size={16} aria-hidden />,
       onClick: opts.onOpen,
     },
     {
       id: 'save',
-      label: 'Save Project',
+      label: t('action.saveProject'),
       icon: <Save size={16} aria-hidden />,
       onClick: opts.onSave,
       disabled: !opts.canSave,
     },
     {
       id: 'export',
-      label: 'Export',
+      label: t('action.export'),
       icon: <Download size={16} aria-hidden />,
       onClick: opts.onExport,
       disabled: !opts.mapImage,
@@ -93,7 +94,7 @@ export function buildOverflowActions(opts: {
     },
     {
       id: 'install',
-      label: 'Install App',
+      label: t('action.installApp'),
       icon: <HardDriveDownload size={16} aria-hidden />,
       onClick: opts.onInstall,
       hidden: !opts.canInstall,
diff --git a/src/config/tools.ts b/src/config/tools.ts
index 7bcf25e..4ecbf80 100644
--- a/src/config/tools.ts
+++ b/src/config/tools.ts
@@ -8,70 +8,72 @@ import {
 } from 'lucide-react'
 import type { LayoutMode } from '../hooks/useLayoutMode'
 import type { Tool } from '../types'
+import { t, type MessageKey } from '../i18n'
 
 export const SWATCHES = ['#e11d48', '#2563eb', '#16a34a', '#f59e0b']
 
 export const TOOLS: {
   id: Tool
-  label: string
-  shortLabel: string
-  tip: string
-  touchTip: string
+  /** Message keys; translate with t() at render time */
+  label: MessageKey
+  shortLabel: MessageKey
+  tip: MessageKey
+  touchTip: MessageKey
   /** Desktop keyboard shortcut; matches toolbar order (1–6) */
   hotkey: string
   icon: typeof Hand
 }[] = [
   {
     id: 'select',
-    label: 'Select',
-    shortLabel: 'Select',
-    tip: 'Click paths or markers to select them. Press Delete to remove.',
-    touchTip: 'Tap paths or markers to select them.',
+    label: 'tool.select',
+    shortLabel: 'tool.select',
+    tip: 'tool.select.tip',
+    touchTip: 'tool.select.touchTip',
     hotkey: '1',
     icon: MousePointer2,
   },
   {
     id: 'pan',
-    label: 'Pan',
-    shortLabel: 'Pan',
-    tip: 'Drag the map to move around. Hold Space or middle mouse for temporary pan.',
-    touchTip: 'Drag with one finger, or use two fingers to pan in any tool.',
+    label: 'tool.pan',
+    shortLabel: 'tool.pan',
+    tip: 'tool.pan.tip',
+    touchTip: 'tool.pan.touchTip',
     hotkey: '2',
     icon: Hand,
   },
   {
     id: 'line',
-    label: 'Draw',
-    shortLabel: 'Draw',
-    tip: 'Click and drag to draw lines on the map.',
-    touchTip: 'Drag your finger to draw lines on the map.',
+    label: 'tool.line',
+    shortLabel: 'tool.line',
+    tip: 'tool.line.tip',
+    touchTip: 'tool.line.touchTip',
     hotkey: '3',
     icon: Pencil,
   },
   {
     id: 'marker',
-    label: 'Marker',
-    shortLabel: 'Marker',
-    tip: 'Click to place a numbered marker with a comment.',
-    touchTip: 'Tap to place a numbered marker with a comment.',
+    label: 'tool.marker',
+    shortLabel: 'tool.marker',
+    tip: 'tool.marker.tip',
+    touchTip: 'tool.marker.touchTip',
     hotkey: '4',
     icon: MapPin,
   },
   {
     id: 'eraser',
-    label: 'Eraser',
-    shortLabel: 'Eraser',
-    tip: 'Click or drag over paths and markers to remove them.',
-    touchTip: 'Tap or drag over paths and markers to remove them.',
+    label: 'tool.eraser',
+    shortLabel: 'tool.eraser',
+    tip: 'tool.eraser.tip',
+    touchTip: 'tool.eraser.touchTip',
     hotkey: '5',
     icon: Eraser,
   },
   {
     id: 'gpx',
-    label: 'Adjust GPX',
-    shortLabel: 'GPX',
-    tip: 'Click the track to add pins, drag to move them, right-click a pin to delete it.',
-    touchTip: 'Tap the track to add pins. Long-press a pin to delete it.',
+    label: 'tool.gpx',
+    shortLabel: 'tool.gpxShort',
+    tip: 'tool.gpx.tip',
+    touchTip: 'tool.gpx.touchTip',
     hotkey: '6',
     icon: Anchor,
   },
@@ -86,9 +88,10 @@ export function getToolByHotkey(key: string): (typeof TOOLS)[number] | undefined
 export function getToolTip(id: Tool, layoutMode: LayoutMode): string {
   const tool = TOOLS.find((t) => t.id === id)
   if (!tool) return ''
-  return layoutMode === 'touch' ? tool.touchTip : tool.tip
+  return t(layoutMode === 'touch' ? tool.touchTip : tool.tip)
 }
 
 export function getToolLabel(id: Tool): string {
-  return TOOLS.find((t) => t.id === id)?.label ?? id
+  const key = TOOLS.find((tool) => tool.id === id)?.label
+  return key ? t(key) : id
 }
diff --git a/src/i18n/i18n.test.ts b/src/i18n/i18n.test.ts
new file mode 100644
index 0000000..b96905f
--- /dev/null
+++ b/src/i18n/i18n.test.ts
@@ -0,0 +1,73 @@
+import { describe, expect, it } from 'vitest'
+import en from '../locales/en.json'
+import { LOCALES, matchLocale, t } from './index'
+
+const locales = import.meta.glob<Record<string, string>>('../locales/*.json', {
+  eager: true,
+  import: 'default',
+})
+
+const placeholders = (text: string) => [...text.matchAll(/\{(\w+)\}/g)].map((m) => m[1]).sort()
+
+describe('locale files', () => {
+  const englishKeys = Object.keys(en).sort()
+
+  it('has a file for every supported language except English', () => {
+    const files = Object.keys(locales).map((path) => path.replace('../locales/', '').replace('.json', ''))
+    for (const { code } of LOCALES) {
+      if (code === 'en') continue
+      expect(files, `missing locales/${code}.json`).toContain(code)
+    }
+  })
+
+  for (const [path, dict] of Object.entries(locales)) {
+    const name = path.replace('../locales/', '')
+
+    it(`${name} has exactly the English keys`, () => {
+      expect(Object.keys(dict).sort()).toEqual(englishKeys)
+    })
+
+    it(`${name} keeps every placeholder from English`, () => {
+      for (const key of englishKeys) {
+        expect(placeholders(dict[key]), key).toEqual(placeholders(en[key as keyof typeof en]))
+      }
+    })
+
+    it(`${name} has no empty translations`, () => {
+      for (const key of englishKeys) {
+        expect(dict[key].trim(), key).not.toBe('')
+      }
+    })
+  }
+})
+
+describe('matchLocale', () => {
+  it('maps browser tags to supported languages', () => {
+    expect(matchLocale('sv-SE')).toBe('sv')
+    expect(matchLocale('nb-NO')).toBe('nb')
+    expect(matchLocale('no')).toBe('nb')
+    expect(matchLocale('nn-NO')).toBe('nb')
+    expect(matchLocale('fi-FI')).toBe('fi')
+    expect(matchLocale('da')).toBe('da')
+    expect(matchLocale('es-MX')).toBe('es')
+    expect(matchLocale('fr-CA')).toBe('fr')
+    expect(matchLocale('pt-PT')).toBe('pt-PT')
+    expect(matchLocale('pt-BR')).toBe('pt-BR')
+    expect(matchLocale('pt')).toBe('pt-BR')
+  })
+
+  it('returns null for unsupported languages', () => {
+    expect(matchLocale('de-DE')).toBeNull()
+    expect(matchLocale('zh-CN')).toBeNull()
+  })
+})
+
+describe('t', () => {
+  it('interpolates named placeholders', () => {
+    expect(t('rotation.degrees', { degrees: 45 })).toBe('45 degrees')
+  })
+
+  it('falls back to the English text for an untranslated key', () => {
+    expect(t('common.close')).toBe('Close')
+  })
+})
diff --git a/src/i18n/index.ts b/src/i18n/index.ts
new file mode 100644
index 0000000..cc9ae7f
--- /dev/null
+++ b/src/i18n/index.ts
@@ -0,0 +1,139 @@
+import { useSyncExternalStore } from 'react'
+import en from '../locales/en.json'
+
+/** Languages the app ships. English is always bundled; the rest load on demand. */
+export const LOCALES = [
+  { code: 'en', name: 'English' },
+  { code: 'sv', name: 'Svenska' },
+  { code: 'nb', name: 'Norsk bokmål' },
+  { code: 'fi', name: 'Suomi' },
+  { code: 'da', name: 'Dansk' },
+  { code: 'es', name: 'Español' },
+  { code: 'fr', name: 'Français' },
+  { code: 'pt-BR', name: 'Português (Brasil)' },
+  { code: 'pt-PT', name: 'Português (Portugal)' },
+] as const
+
+export type Locale = (typeof LOCALES)[number]['code']
+export type MessageKey = keyof typeof en
+/** Plain text, or per-plural-category text for counted messages */
+export type Message = string | { one: string; other: string }
+/** Every locale file must satisfy this, so a missing key fails the type check */
+export type Dictionary = Record<MessageKey, Message>
+export type MessageParams = Record<string, string | number>
+
+const STORAGE_KEY = 'o-analysis-locale'
+
+const loaders = import.meta.glob<{ default: Dictionary }>('../locales/*.json')
+
+let currentLocale: Locale = 'en'
+let current: Dictionary = en as Dictionary
+const listeners = new Set<() => void>()
+
+function isLocale(value: string): value is Locale {
+  return LOCALES.some((l) => l.code === value)
+}
+
+/**
+ * Picks the closest supported language for a browser language tag.
+ * Norwegian nn/no map to Bokmål; any Portuguese region other than Portugal
+ * maps to Brazilian Portuguese, which is the larger audience.
+ */
+export function matchLocale(tag: string): Locale | null {
+  const lower = tag.toLowerCase()
+  if (lower === 'pt-pt') return 'pt-PT'
+  if (lower === 'pt-br') return 'pt-BR'
+  const base = lower.split('-')[0]
+  if (base === 'pt') return lower.endsWith('-pt') ? 'pt-PT' : 'pt-BR'
+  if (base === 'no' || base === 'nn' || base === 'nb') return 'nb'
+  if (isLocale(base)) return base
+  return null
+}
+
+export function detectLocale(): Locale {
+  try {
+    const saved = globalThis.localStorage?.getItem(STORAGE_KEY)
+    if (saved && isLocale(saved)) return saved
+  } catch {
+    // Storage can be blocked (private mode, disabled site data); fall through to the browser
+  }
+  for (const tag of globalThis.navigator?.languages ?? []) {
+    const match = matchLocale(tag)
+    if (match) return match
+  }
+  return 'en'
+}
+
+async function loadDictionary(locale: Locale): Promise<Dictionary> {
+  if (locale === 'en') return en as Dictionary
+  const loader = loaders[`../locales/${locale}.json`]
+  if (!loader) return en as Dictionary // unknown file: fall back rather than show raw keys
+  return (await loader()).default
+}
+
+function applyDocumentLanguage(locale: Locale): void {
+  if (typeof document === 'undefined') return
+  document.documentElement.lang = locale
+  document.documentElement.dir = 'ltr'
+}
+
+/** Loads the saved or detected language before the first render. */
+export async function initI18n(): Promise<void> {
+  await setLocale(detectLocale(), { persist: false })
+}
+
+/** Switches language. Components re-render through useLocale(). */
+export async function setLocale(
+  locale: Locale,
+  options: { persist?: boolean } = { persist: true },
+): Promise<void> {
+  current = await loadDictionary(locale)
+  currentLocale = locale
+  applyDocumentLanguage(locale)
+  if (options.persist !== false) {
+    try {
+      globalThis.localStorage?.setItem(STORAGE_KEY, locale)
+    } catch {
+      // Not saved; the choice lasts for this visit only
+    }
+  }
+  for (const listener of listeners) listener()
+}
+
+export function getLocale(): Locale {
+  return currentLocale
+}
+
+function interpolate(text: string, params: MessageParams = {}): string {
+  return text.replace(/\{(\w+)\}/g, (match, name: string) =>
+    name in params ? String(params[name]) : match,
+  )
+}
+
+/** Translates a message. Counted messages pick the plural form from the `count` param. */
+export function t(key: MessageKey, params?: MessageParams): string {
+  const message: Message = current[key] ?? (en as Dictionary)[key]
+  if (typeof message === 'string') return interpolate(message, params)
+  const count = Number(params?.count ?? 0)
+  const category = new Intl.PluralRules(currentLocale).select(count)
+  return interpolate(category === 'one' ? message.one : message.other, params)
+}
+
+function subscribe(listener: () => void): () => void {
+  listeners.add(listener)
+  return () => listeners.delete(listener)
+}
+
+/** Returns the translator and re-renders the caller when the language changes. */
+export function useT(): (key: MessageKey, params?: MessageParams) => string {
+  useSyncExternalStore(subscribe, getLocale, getLocale)
+  return t
+}
+
+/** Formats a number for the app language, e.g. 12,5 in Swedish and 12.5 in English. */
+export function formatNumber(value: number, fractionDigits = 0): string {
+  return new Intl.NumberFormat(currentLocale, {
+    minimumFractionDigits: fractionDigits,
+    maximumFractionDigits: fractionDigits,
+  }).format(value)
+}
diff --git a/src/index.css b/src/index.css
index de05f79..2fd7c20 100644
--- a/src/index.css
+++ b/src/index.css
@@ -1,4 +1,5 @@
 :root {
+  --palette-width: 80px;
   --text: #6b6375;
   --text-h: #08060d;
   --bg: #fff;
@@ -119,3 +120,34 @@ h2 {
   outline: 2px solid var(--accent-border);
   outline-offset: 2px;
 }
+
+/* Language picker */
+.statusbar-language,
+.style-sheet-language {
+  font: inherit;
+  color: var(--text);
+  background: transparent;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 2px 4px;
+  max-width: 180px;
+}
+
+.style-sheet-language {
+  display: block;
+  width: 100%;
+  max-width: none;
+  margin: 8px 0;
+  padding: 8px;
+  font-size: 15px;
+}
+
+/* Text in the touch Style sheet: sans-serif, label wraps above the slider instead of colliding with it */
+.style-sheet-text-size {
+  font-family: var(--sans);
+  flex-wrap: wrap;
+}
+
+.style-sheet-text-size > span:first-child {
+  flex: 1 1 100%;
+}
diff --git a/src/locales/da.json b/src/locales/da.json
new file mode 100644
index 0000000..6c7b1d1
--- /dev/null
+++ b/src/locales/da.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Redigér GPX",
+  "action.editImage": "Redigér billede",
+  "action.export": "Eksportér",
+  "action.importGpx": "Importér GPX",
+  "action.importImage": "Importér billede",
+  "action.installApp": "Installér appen",
+  "action.newProject": "Nyt projekt",
+  "action.openProject": "Åbn projekt",
+  "action.projects": "Projekter",
+  "action.saveProject": "Gem projekt",
+  "action.updateApp": "Opdatér appen",
+  "canvas.importHintDrop": "Importér et kortbillede for at komme i gang, eller slip en fil her.",
+  "canvas.importHintTouch": "Importér et kortbillede for at komme i gang.",
+  "canvas.importMap": "Importér kort",
+  "canvas.loadingSample": "Indlæser eksempel…",
+  "canvas.noMap": "Intet kort indlæst",
+  "canvas.openSample": "Åbn eksempelprojekt",
+  "color.channel": "{channel}-kanal",
+  "color.channelValue": "{channel}-værdi",
+  "color.custom": "Egen farve",
+  "color.hex": "Hex",
+  "color.hexAria": "Hex-farve",
+  "common.apply": "Anvend",
+  "common.cancel": "Annullér",
+  "common.close": "Luk",
+  "common.delete": "Slet",
+  "common.dismiss": "Luk",
+  "common.errorGeneric": "Noget gik galt",
+  "common.loading": "Indlæser…",
+  "common.rename": "Omdøb",
+  "error.body": "O-Analysis stødte på en uventet fejl. Genindlæsning af siden hjælper normalt.",
+  "error.damagedEntry": "Ugyldig {label} i projektfilen (post {index} er beskadiget)",
+  "error.decodeImage": "Billedfilen kunne ikke læses",
+  "error.decodeMap": "Kortbilledet kunne ikke læses",
+  "error.exportTooLarge": "Kortet er for stort til at blive eksporteret på denne enhed",
+  "error.gpxImport": "GPX-importen mislykkedes",
+  "error.imageImport": "Billedimporten mislykkedes",
+  "error.imageTooLarge": "Billedet er for stort ({size}). Den maksimale størrelse er 20 MB.",
+  "error.invalidEntry": "Ugyldig {label} i projektfilen",
+  "error.invalidMap": "Ugyldigt kortbillede i projektfilen",
+  "error.invalidName": "Ugyldigt projektnavn i projektfilen",
+  "error.invalidRotation": "Ugyldig rotation i projektfilen",
+  "error.labelAnnotations": "annoteringer",
+  "error.labelDrawings": "tegninger",
+  "error.labelTracks": "GPX-spor",
+  "error.loadSample": "Eksempelprojektet kunne ikke indlæses",
+  "error.noGpxPoints": "GPX-filen indeholder ingen brugbare sporpunkter",
+  "error.notGpx": "Ikke en gyldig GPX-fil",
+  "error.notImage": "”{name}” er ikke en billedfil",
+  "error.notJson": "Projektfilen er ikke gyldig JSON",
+  "error.notOurs": "Ikke en O-Analysis-projektfil",
+  "error.notProjectFile": "Ikke en projektfil – forventede {ext}",
+  "error.nothingToSave": "Intet at gemme – importér et kort eller tilføj indhold først",
+  "error.openProject": "Projektfilen kunne ikke åbnes",
+  "error.projectNotFound": "Projektet kunne ikke findes",
+  "error.readImage": "Billedfilen kunne ikke læses",
+  "error.reload": "Genindlæs siden",
+  "error.renderExport": "Eksportbilledet kunne ikke tegnes",
+  "error.sampleNotFound": "Eksempelprojektet blev ikke fundet",
+  "error.title": "Noget gik galt",
+  "error.unsupportedFile": "Filtypen understøttes ikke: ”{name}”",
+  "error.version": "Projektversionen understøttes ikke: {version}",
+  "export.download": "Download PNG",
+  "export.exporting": "Eksporterer…",
+  "export.failed": "Eksporten mislykkedes – prøv igen",
+  "export.fit": "Tilpas",
+  "export.generating": "Genererer forhåndsvisning…",
+  "export.hint": "Rul for at zoome · træk for at flytte",
+  "export.includeSidebar": "Medtag annoteringspanelet",
+  "export.loadingPreview": "Indlæser forhåndsvisning…",
+  "export.previewAlt": "Forhåndsvisning af eksport",
+  "export.resetZoom": "Nulstil zoom",
+  "export.scaleNotice": "Kortet er større, end denne enhed kan eksportere i fuld størrelse, så PNG-filen bliver {percent} % af den oprindelige opløsning.",
+  "export.sidebarWithComments": "Kommentarerne vises på kortet – slå panelet fra for at undgå dubletter.",
+  "export.sidebarWithLabels": "Panelet viser hver markørbogstav med sin kommentar.",
+  "export.textSize": "Tekststørrelse",
+  "export.title": "Eksportér",
+  "export.zoomIn": "Zoom ind",
+  "export.zoomOut": "Zoom ud",
+  "gpx.adjustMap": "Justér på kortet",
+  "gpx.applyCrop": "Anvend beskæring",
+  "gpx.confirm": "Bekræft",
+  "gpx.crop": "Beskær",
+  "gpx.cropAria": "Beskær spor",
+  "gpx.cropError": "Markeringen skal indeholde mindst 2 punkter.",
+  "gpx.cropTitle": "Beskær spor",
+  "gpx.empty": "Ingen GPX-spor indlæst.",
+  "gpx.fast": "Hurtig (grøn)",
+  "gpx.highHr": "Høj puls (lys rød)",
+  "gpx.hr": "Puls",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Linjestil",
+  "gpx.lowHr": "Lav puls (mørk rød)",
+  "gpx.noTiming": "Ingen tidsdata i denne GPX-fil – beskær efter afstand",
+  "gpx.opacity": "Opacitet",
+  "gpx.opacityShort": "Opac.",
+  "gpx.pace": "Tempo",
+  "gpx.remove": "Fjern",
+  "gpx.removeAria": "Fjern spor",
+  "gpx.slow": "Langsom (rød)",
+  "gpx.solid": "Helt optrukket",
+  "gpx.strokeWidth": "Linjebredde",
+  "gpx.tipAdjust": "Skift til kortet og træk ankerpunkterne",
+  "gpx.tipCrop": "Beskær sporets start og slutning",
+  "gpx.tipRemove": "Fjern dette spor fra projektet",
+  "gpx.title": "GPX-spor",
+  "gpx.toastTapHint": "Tryk på sporet for at tilføje punkter. Tryk længe på et punkt for at slette det.",
+  "gpx.trackColour": "Sporfarve {color}",
+  "gpx.upload": "Upload",
+  "gpx.width": "Bredde",
+  "language.label": "Sprog",
+  "legal.binding": "Den engelske version af dokumentet er den bindende tekst. Oversættelserne er kun til orientering.",
+  "legal.lastUpdated": "Senest opdateret: {date}",
+  "library.deleteAria": "Slet {name}",
+  "library.empty": "Ingen gemte projekter endnu. Importér et kort for at starte et.",
+  "library.noMap": "Intet kort endnu",
+  "library.open": "Åben",
+  "library.renameAria": "Omdøb {name}",
+  "library.title": "Projekter",
+  "library.updated": "{map} · Opdateret {date}",
+  "menu.file": "Fil",
+  "menu.legal": "Juridisk",
+  "menu.menu": "Menu",
+  "menu.more": "Flere handlinger",
+  "menu.privacy": "Privatlivspolitik",
+  "menu.terms": "Servicevilkår",
+  "notes.centerHint": "Klik for at centrere på kortet",
+  "notes.commentPlaceholder": "Tilføj en kommentar…",
+  "notes.comments": "Kommentarer",
+  "notes.commentsHint": "Vis kommentarer direkte på kortet. Træk i højre kant af en valgt kommentar for at ændre bredden.",
+  "notes.deleteAria": "Slet annotering {label}",
+  "notes.displayAria": "Visning af kortmarkører",
+  "notes.empty": "Ingen annoteringer endnu. Brug markørværktøjet til at tilføje kommentarer på kortet.",
+  "notes.heading": "Annoteringer",
+  "notes.labels": "Etiketter",
+  "notes.labelsHint": "Vis bogstavetiketter på kortmarkørerne",
+  "notes.removeHint": "Fjern denne markør",
+  "notes.toggle": "Noter",
+  "notes.toggleAria": "Vis eller skjul annoteringer",
+  "project.untitled": "Unavngivet projekt",
+  "pwa.dismissUpdate": "Luk opdateringsbeskeden",
+  "pwa.updateAvailable": "En ny version af O-Analysis er tilgængelig.",
+  "pwa.updateNow": "Opdatér nu",
+  "rotation.degrees": "{degrees} grader",
+  "rotation.group": "Kortrotation",
+  "rotation.label": "Rotation",
+  "rotation.reset": "Nulstil rotation",
+  "rotation.resetAria": "Nulstil rotationen til 0 grader",
+  "rotation.rotate": "Roter",
+  "save.failed": "Automatisk gemning mislykkedes",
+  "save.saved": "Gemt {time}",
+  "save.saving": "Gemmer…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "af Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Tilpas kortet til skærmen",
+  "status.fitHint": "Tilpas kortet til skærmen",
+  "status.legal": "Juridisk",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Privatliv",
+  "status.terms": "Vilkår",
+  "status.textSize": "Tekststørrelse",
+  "status.textSizeShort": "Tekst",
+  "status.tool": "Værktøj: {tool}",
+  "status.zoomIn": "Zoom ind",
+  "status.zoomOut": "Zoom ud",
+  "stroke.color": "Farve",
+  "stroke.colorAria": "Farve {color}",
+  "stroke.custom": "Egen farve",
+  "stroke.customHint": "Vælg en egen farve",
+  "stroke.opacity": "Opacitet",
+  "stroke.opacityHint": "Gennemsigtighed for tegnede linjer og markører",
+  "stroke.useColor": "Brug {color}",
+  "stroke.width": "Bredde",
+  "stroke.widthHint": "Linje- og markørbredde",
+  "style.commentTextSize": "Tekststørrelse for kommentarer",
+  "tool.eraser": "Viskelæder",
+  "tool.eraser.tip": "Klik eller træk hen over linjer og markører for at fjerne dem.",
+  "tool.eraser.touchTip": "Tryk eller træk hen over linjer og markører for at fjerne dem.",
+  "tool.gpx": "Justér GPX",
+  "tool.gpx.tip": "Klik på sporet for at tilføje punkter, træk for at flytte dem, og højreklik på et punkt for at slette det.",
+  "tool.gpx.touchTip": "Tryk på sporet for at tilføje punkter. Tryk længe på et punkt for at slette det.",
+  "tool.gpxNeedsFile": "Importér en GPX-fil først",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Tegn",
+  "tool.line.tip": "Klik og træk for at tegne linjer på kortet.",
+  "tool.line.touchTip": "Træk fingeren for at tegne linjer på kortet.",
+  "tool.marker": "Markør",
+  "tool.marker.tip": "Klik for at placere en nummereret markør med en kommentar.",
+  "tool.marker.touchTip": "Tryk for at placere en nummereret markør med en kommentar.",
+  "tool.pan": "Flyt",
+  "tool.pan.tip": "Træk kortet for at bevæge dig rundt. Hold mellemrum eller midterknappen nede for midlertidig flytning.",
+  "tool.pan.touchTip": "Træk med ét finger, eller brug to fingre for at flytte i alle værktøjer.",
+  "tool.select": "Vælg",
+  "tool.select.tip": "Klik på linjer eller markører for at vælge dem. Tryk på Delete for at fjerne.",
+  "tool.select.touchTip": "Tryk på linjer eller markører for at vælge dem.",
+  "toolbar.annotations": "Annoteringer",
+  "toolbar.drawingTools": "Tegneværktøjer",
+  "toolbar.notes": "Noter",
+  "toolbar.strokeSettings": "Linjeindstillinger",
+  "toolbar.style": "Stil",
+  "toolbar.viewAndStroke": "Visning og linjeindstillinger",
+  "top.dismissError": "Luk fejlbeskeden",
+  "top.editGpxHint": "Ændr sporfarve, bredde eller justering",
+  "top.exportDisabled": "Importér et kortbillede, før du eksporterer",
+  "top.exportHint": "Forhåndsvis og download kortet med tegninger og annoteringer",
+  "top.history": "Historik",
+  "top.importGpxHint": "Importér en GPX-fil for at lægge en rute over kortet",
+  "top.importImageHint": "Upload et kortbillede – PNG, JPG, eller slip en fil på lærredet",
+  "top.installApp": "Installér appen",
+  "top.installHint": "Installér O-Analysis som en desktopapp",
+  "top.new": "Ny",
+  "top.newHint": "Ryd lærredet og start forfra",
+  "top.open": "Åbn",
+  "top.openHint": "Åbn et gemt projekt ({ext})",
+  "top.projectName": "Projektnavn",
+  "top.projects": "Projekter",
+  "top.projectsHint": "Skift mellem gemte projekter",
+  "top.redo": "Gentag",
+  "top.redoHint": "Gentag (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Erstat det aktuelle kortbillede",
+  "top.save": "Gem",
+  "top.saveDisabled": "Intet at gemme endnu – importér et kort eller tilføj annoteringer først",
+  "top.saveHint": "Gem projektet som {ext}",
+  "top.undo": "Fortryd",
+  "top.undoHint": "Fortryd sidste handling (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Opdatér appen",
+  "top.updateHint": "Genindlæs for at bruge den seneste version",
+  "touch.dismissTips": "Luk tipsene",
+  "touch.tips": "Knib for at zoome, brug to fingre for at flytte. Tryk på et værktøj og derefter på kortet for at tegne eller placere markører."
+}
diff --git a/src/locales/en.json b/src/locales/en.json
new file mode 100644
index 0000000..4d6ea43
--- /dev/null
+++ b/src/locales/en.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Edit GPX",
+  "action.editImage": "Edit Image",
+  "action.export": "Export",
+  "action.importGpx": "Import GPX",
+  "action.importImage": "Import Image",
+  "action.installApp": "Install App",
+  "action.newProject": "New Project",
+  "action.openProject": "Open Project",
+  "action.projects": "Projects",
+  "action.saveProject": "Save Project",
+  "action.updateApp": "Update App",
+  "canvas.importHintDrop": "Import a map image to get started, or drop a file here.",
+  "canvas.importHintTouch": "Import a map image to get started.",
+  "canvas.importMap": "Import Map",
+  "canvas.loadingSample": "Loading sample…",
+  "canvas.noMap": "No map loaded",
+  "canvas.openSample": "Open Sample Project",
+  "color.channel": "{channel} channel",
+  "color.channelValue": "{channel} value",
+  "color.custom": "Custom color",
+  "color.hex": "Hex",
+  "color.hexAria": "Hex color",
+  "common.apply": "Apply",
+  "common.cancel": "Cancel",
+  "common.close": "Close",
+  "common.delete": "Delete",
+  "common.dismiss": "Dismiss",
+  "common.errorGeneric": "Something went wrong",
+  "common.loading": "Loading…",
+  "common.rename": "Rename",
+  "error.body": "O-Analysis ran into an unexpected error. Reloading the page usually fixes this.",
+  "error.damagedEntry": "Invalid {label} in project file (entry {index} is damaged)",
+  "error.decodeImage": "Could not decode the image file",
+  "error.decodeMap": "Could not decode map image",
+  "error.exportTooLarge": "This map is too large to export on this device",
+  "error.gpxImport": "GPX import failed",
+  "error.imageImport": "Image import failed",
+  "error.imageTooLarge": "Image is too large ({size}). Maximum size is 20MB.",
+  "error.invalidEntry": "Invalid {label} in project file",
+  "error.invalidMap": "Invalid map image in project file",
+  "error.invalidName": "Invalid project name in project file",
+  "error.invalidRotation": "Invalid rotation in project file",
+  "error.labelAnnotations": "annotations",
+  "error.labelDrawings": "drawings",
+  "error.labelTracks": "GPX tracks",
+  "error.loadSample": "Failed to load sample project",
+  "error.noGpxPoints": "GPX file contains no usable track points",
+  "error.notGpx": "Not a valid GPX file",
+  "error.notImage": "\"{name}\" is not an image file",
+  "error.notJson": "Project file is not valid JSON",
+  "error.notOurs": "Not an O-Analysis project file",
+  "error.notProjectFile": "Not a project file — expected {ext}",
+  "error.nothingToSave": "Nothing to save — import a map or add content first",
+  "error.openProject": "Failed to open project file",
+  "error.projectNotFound": "That project could not be found",
+  "error.readImage": "Could not read the image file",
+  "error.reload": "Reload page",
+  "error.renderExport": "Failed to render export image",
+  "error.sampleNotFound": "Sample project not found",
+  "error.title": "Something went wrong",
+  "error.unsupportedFile": "Unsupported file type: \"{name}\"",
+  "error.version": "Unsupported project version: {version}",
+  "export.download": "Download PNG",
+  "export.exporting": "Exporting…",
+  "export.failed": "Export failed — please try again",
+  "export.fit": "Fit",
+  "export.generating": "Generating preview…",
+  "export.hint": "Scroll to zoom · drag to pan",
+  "export.includeSidebar": "Include annotation sidebar",
+  "export.loadingPreview": "Loading preview…",
+  "export.previewAlt": "Export preview",
+  "export.resetZoom": "Reset zoom",
+  "export.scaleNotice": "This map is larger than this device can export at full size, so the PNG will be {percent}% of native resolution.",
+  "export.sidebarWithComments": "Comments are shown on the map — turn off the sidebar to avoid duplicating them.",
+  "export.sidebarWithLabels": "The sidebar lists each marker letter with its comment.",
+  "export.textSize": "Text size",
+  "export.title": "Export",
+  "export.zoomIn": "Zoom in",
+  "export.zoomOut": "Zoom out",
+  "gpx.adjustMap": "Adjust on map",
+  "gpx.applyCrop": "Apply crop",
+  "gpx.confirm": "Confirm",
+  "gpx.crop": "Crop",
+  "gpx.cropAria": "Crop track",
+  "gpx.cropError": "Selection must include at least 2 points.",
+  "gpx.cropTitle": "Crop track",
+  "gpx.empty": "No GPX tracks loaded.",
+  "gpx.fast": "Fast (green)",
+  "gpx.highHr": "High HR (bright red)",
+  "gpx.hr": "HR",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Line style",
+  "gpx.lowHr": "Low HR (dark red)",
+  "gpx.noTiming": "No timing data in this GPX — crop by distance",
+  "gpx.opacity": "Opacity",
+  "gpx.opacityShort": "Opac",
+  "gpx.pace": "Pace",
+  "gpx.remove": "Remove",
+  "gpx.removeAria": "Remove track",
+  "gpx.slow": "Slow (red)",
+  "gpx.solid": "Solid",
+  "gpx.strokeWidth": "Stroke width",
+  "gpx.tipAdjust": "Switch to map and drag anchor pins",
+  "gpx.tipCrop": "Crop start and end of track",
+  "gpx.tipRemove": "Remove this track from the project",
+  "gpx.title": "GPX tracks",
+  "gpx.toastTapHint": "Tap the track to add pins. Long-press a pin to delete.",
+  "gpx.trackColour": "Track colour {color}",
+  "gpx.upload": "Upload",
+  "gpx.width": "Width",
+  "language.label": "Language",
+  "legal.binding": "The English version of this document is the binding text. Translations are provided for convenience.",
+  "legal.lastUpdated": "Last updated: {date}",
+  "library.deleteAria": "Delete {name}",
+  "library.empty": "No saved projects yet. Import a map to start one.",
+  "library.noMap": "No map yet",
+  "library.open": "Open",
+  "library.renameAria": "Rename {name}",
+  "library.title": "Projects",
+  "library.updated": "{map} · Updated {date}",
+  "menu.file": "File",
+  "menu.legal": "Legal",
+  "menu.menu": "Menu",
+  "menu.more": "More actions",
+  "menu.privacy": "Privacy Policy",
+  "menu.terms": "Terms of Service",
+  "notes.centerHint": "Click to center on the map",
+  "notes.commentPlaceholder": "Add a comment…",
+  "notes.comments": "Comments",
+  "notes.commentsHint": "Show inline comments on the map. Drag the right edge of a selected comment to change its width.",
+  "notes.deleteAria": "Delete annotation {label}",
+  "notes.displayAria": "Map marker display",
+  "notes.empty": "No annotations yet. Use the marker tool to add comments to the map.",
+  "notes.heading": "Annotations",
+  "notes.labels": "Labels",
+  "notes.labelsHint": "Show letter labels on map markers",
+  "notes.removeHint": "Remove this marker",
+  "notes.toggle": "Notes",
+  "notes.toggleAria": "Toggle annotations",
+  "project.untitled": "Untitled project",
+  "pwa.dismissUpdate": "Dismiss update notice",
+  "pwa.updateAvailable": "A new version of O-Analysis is available.",
+  "pwa.updateNow": "Update now",
+  "rotation.degrees": "{degrees} degrees",
+  "rotation.group": "Canvas rotation",
+  "rotation.label": "Rotation",
+  "rotation.reset": "Reset rotation",
+  "rotation.resetAria": "Reset rotation to 0 degrees",
+  "rotation.rotate": "Rotate",
+  "save.failed": "Autosave failed",
+  "save.saved": "Saved {time}",
+  "save.saving": "Saving…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "by Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom}%. Fit map to screen",
+  "status.fitHint": "Fit the map to the screen",
+  "status.legal": "Legal",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Privacy",
+  "status.terms": "Terms",
+  "status.textSize": "Text Size",
+  "status.textSizeShort": "Text",
+  "status.tool": "Tool: {tool}",
+  "status.zoomIn": "Zoom in",
+  "status.zoomOut": "Zoom out",
+  "stroke.color": "Color",
+  "stroke.colorAria": "Color {color}",
+  "stroke.custom": "Custom color",
+  "stroke.customHint": "Pick a custom color",
+  "stroke.opacity": "Opacity",
+  "stroke.opacityHint": "Transparency for drawn lines and markers",
+  "stroke.useColor": "Use {color}",
+  "stroke.width": "Width",
+  "stroke.widthHint": "Line and marker stroke width",
+  "style.commentTextSize": "Comment text size",
+  "tool.eraser": "Eraser",
+  "tool.eraser.tip": "Click or drag over paths and markers to remove them.",
+  "tool.eraser.touchTip": "Tap or drag over paths and markers to remove them.",
+  "tool.gpx": "Adjust GPX",
+  "tool.gpx.tip": "Click the track to add pins, drag to move them, right-click a pin to delete it.",
+  "tool.gpx.touchTip": "Tap the track to add pins. Long-press a pin to delete it.",
+  "tool.gpxNeedsFile": "Import a GPX file first",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Draw",
+  "tool.line.tip": "Click and drag to draw lines on the map.",
+  "tool.line.touchTip": "Drag your finger to draw lines on the map.",
+  "tool.marker": "Marker",
+  "tool.marker.tip": "Click to place a numbered marker with a comment.",
+  "tool.marker.touchTip": "Tap to place a numbered marker with a comment.",
+  "tool.pan": "Pan",
+  "tool.pan.tip": "Drag the map to move around. Hold Space or middle mouse for temporary pan.",
+  "tool.pan.touchTip": "Drag with one finger, or use two fingers to pan in any tool.",
+  "tool.select": "Select",
+  "tool.select.tip": "Click paths or markers to select them. Press Delete to remove.",
+  "tool.select.touchTip": "Tap paths or markers to select them.",
+  "toolbar.annotations": "Annotations",
+  "toolbar.drawingTools": "Drawing tools",
+  "toolbar.notes": "Notes",
+  "toolbar.strokeSettings": "Stroke settings",
+  "toolbar.style": "Style",
+  "toolbar.viewAndStroke": "View & stroke settings",
+  "top.dismissError": "Dismiss error",
+  "top.editGpxHint": "Change track colours, width, or alignment",
+  "top.exportDisabled": "Import a map image before exporting",
+  "top.exportHint": "Preview and download the map with drawings and annotations",
+  "top.history": "History",
+  "top.importGpxHint": "Import a GPX file to overlay a route on the map",
+  "top.importImageHint": "Upload a map image — PNG, JPG, or drop a file on the canvas",
+  "top.installApp": "Install App",
+  "top.installHint": "Install O-Analysis as a desktop app",
+  "top.new": "New",
+  "top.newHint": "Clear the canvas and start fresh",
+  "top.open": "Open",
+  "top.openHint": "Open a saved project ({ext})",
+  "top.projectName": "Project name",
+  "top.projects": "Projects",
+  "top.projectsHint": "Switch between saved projects",
+  "top.redo": "Redo",
+  "top.redoHint": "Redo (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Replace the current map image",
+  "top.save": "Save",
+  "top.saveDisabled": "Nothing to save yet — import a map or add annotations first",
+  "top.saveHint": "Save your project as {ext}",
+  "top.undo": "Undo",
+  "top.undoHint": "Undo last action (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Update App",
+  "top.updateHint": "Reload to use the latest version",
+  "touch.dismissTips": "Dismiss tips",
+  "touch.tips": "Pinch to zoom, use two fingers to pan. Tap a tool, then tap the map to draw or place markers."
+}
diff --git a/src/locales/es.json b/src/locales/es.json
new file mode 100644
index 0000000..4a65b9f
--- /dev/null
+++ b/src/locales/es.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Editar GPX",
+  "action.editImage": "Editar imagen",
+  "action.export": "Exportar",
+  "action.importGpx": "Importar GPX",
+  "action.importImage": "Importar imagen",
+  "action.installApp": "Instalar la app",
+  "action.newProject": "Nuevo proyecto",
+  "action.openProject": "Abrir proyecto",
+  "action.projects": "Proyectos",
+  "action.saveProject": "Guardar proyecto",
+  "action.updateApp": "Actualizar la app",
+  "canvas.importHintDrop": "Importa una imagen de mapa para empezar, o suelta un archivo aquí.",
+  "canvas.importHintTouch": "Importa una imagen de mapa para empezar.",
+  "canvas.importMap": "Importar mapa",
+  "canvas.loadingSample": "Cargando ejemplo…",
+  "canvas.noMap": "No hay ningún mapa cargado",
+  "canvas.openSample": "Abrir proyecto de ejemplo",
+  "color.channel": "Canal {channel}",
+  "color.channelValue": "Valor de {channel}",
+  "color.custom": "Color personalizado",
+  "color.hex": "Hex",
+  "color.hexAria": "Color hexadecimal",
+  "common.apply": "Aplicar",
+  "common.cancel": "Cancelar",
+  "common.close": "Cerrar",
+  "common.delete": "Eliminar",
+  "common.dismiss": "Descartar",
+  "common.errorGeneric": "Algo salió mal",
+  "common.loading": "Cargando…",
+  "common.rename": "Cambiar nombre",
+  "error.body": "O-Analysis encontró un error inesperado. Recargar la página suele solucionarlo.",
+  "error.damagedEntry": "{label} no válido en el archivo del proyecto (la entrada {index} está dañada)",
+  "error.decodeImage": "No se pudo leer el archivo de imagen",
+  "error.decodeMap": "No se pudo leer la imagen del mapa",
+  "error.exportTooLarge": "El mapa es demasiado grande para exportarlo en este dispositivo",
+  "error.gpxImport": "No se pudo importar el GPX",
+  "error.imageImport": "No se pudo importar la imagen",
+  "error.imageTooLarge": "La imagen es demasiado grande ({size}). El tamaño máximo es de 20 MB.",
+  "error.invalidEntry": "{label} no válido en el archivo del proyecto",
+  "error.invalidMap": "Imagen de mapa no válida en el archivo del proyecto",
+  "error.invalidName": "Nombre de proyecto no válido en el archivo del proyecto",
+  "error.invalidRotation": "Rotación no válida en el archivo del proyecto",
+  "error.labelAnnotations": "anotaciones",
+  "error.labelDrawings": "dibujos",
+  "error.labelTracks": "recorridos GPX",
+  "error.loadSample": "No se pudo cargar el proyecto de ejemplo",
+  "error.noGpxPoints": "El archivo GPX no contiene puntos de recorrido utilizables",
+  "error.notGpx": "No es un archivo GPX válido",
+  "error.notImage": "«{name}» no es un archivo de imagen",
+  "error.notJson": "El archivo del proyecto no es JSON válido",
+  "error.notOurs": "No es un archivo de proyecto de O-Analysis",
+  "error.notProjectFile": "No es un archivo de proyecto; se esperaba {ext}",
+  "error.nothingToSave": "No hay nada que guardar; importa un mapa o añade contenido primero",
+  "error.openProject": "No se pudo abrir el archivo del proyecto",
+  "error.projectNotFound": "No se pudo encontrar el proyecto",
+  "error.readImage": "No se pudo leer el archivo de imagen",
+  "error.reload": "Recargar página",
+  "error.renderExport": "No se pudo generar la imagen de exportación",
+  "error.sampleNotFound": "No se encontró el proyecto de ejemplo",
+  "error.title": "Algo salió mal",
+  "error.unsupportedFile": "Tipo de archivo no compatible: «{name}»",
+  "error.version": "Versión de proyecto no compatible: {version}",
+  "export.download": "Descargar PNG",
+  "export.exporting": "Exportando…",
+  "export.failed": "La exportación falló; inténtalo de nuevo",
+  "export.fit": "Ajustar",
+  "export.generating": "Generando vista previa…",
+  "export.hint": "Desplázate para hacer zoom · arrastra para mover",
+  "export.includeSidebar": "Incluir panel de anotaciones",
+  "export.loadingPreview": "Cargando vista previa…",
+  "export.previewAlt": "Vista previa de la exportación",
+  "export.resetZoom": "Restablecer zoom",
+  "export.scaleNotice": "El mapa es más grande de lo que este dispositivo puede exportar a tamaño completo, así que el PNG será del {percent} % de la resolución original.",
+  "export.sidebarWithComments": "Los comentarios aparecen en el mapa; desactiva el panel para no duplicarlos.",
+  "export.sidebarWithLabels": "El panel muestra cada letra de marcador con su comentario.",
+  "export.textSize": "Tamaño del texto",
+  "export.title": "Exportar",
+  "export.zoomIn": "Acercar",
+  "export.zoomOut": "Alejar",
+  "gpx.adjustMap": "Ajustar en el mapa",
+  "gpx.applyCrop": "Aplicar recorte",
+  "gpx.confirm": "Confirmar",
+  "gpx.crop": "Recortar",
+  "gpx.cropAria": "Recortar recorrido",
+  "gpx.cropError": "La selección debe incluir al menos 2 puntos.",
+  "gpx.cropTitle": "Recortar recorrido",
+  "gpx.empty": "No hay recorridos GPX cargados.",
+  "gpx.fast": "Rápido (verde)",
+  "gpx.highHr": "FC alta (rojo intenso)",
+  "gpx.hr": "FC",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Estilo de línea",
+  "gpx.lowHr": "FC baja (rojo oscuro)",
+  "gpx.noTiming": "Este GPX no tiene datos de tiempo; recorta por distancia",
+  "gpx.opacity": "Opacidad",
+  "gpx.opacityShort": "Opac.",
+  "gpx.pace": "Ritmo",
+  "gpx.remove": "Quitar",
+  "gpx.removeAria": "Quitar recorrido",
+  "gpx.slow": "Lento (rojo)",
+  "gpx.solid": "Sólido",
+  "gpx.strokeWidth": "Grosor de línea",
+  "gpx.tipAdjust": "Cambia al mapa y arrastra los pines de anclaje",
+  "gpx.tipCrop": "Recorta el inicio y el final del recorrido",
+  "gpx.tipRemove": "Quita este recorrido del proyecto",
+  "gpx.title": "Recorridos GPX",
+  "gpx.toastTapHint": "Toca el recorrido para añadir pines. Mantén pulsado un pin para eliminarlo.",
+  "gpx.trackColour": "Color del recorrido {color}",
+  "gpx.upload": "Subir",
+  "gpx.width": "Ancho",
+  "language.label": "Idioma",
+  "legal.binding": "La versión inglesa de este documento es el texto vinculante. Las traducciones se ofrecen solo como referencia.",
+  "legal.lastUpdated": "Última actualización: {date}",
+  "library.deleteAria": "Eliminar {name}",
+  "library.empty": "Todavía no hay proyectos guardados. Importa un mapa para empezar uno.",
+  "library.noMap": "Sin mapa todavía",
+  "library.open": "Abierto",
+  "library.renameAria": "Cambiar el nombre de {name}",
+  "library.title": "Proyectos",
+  "library.updated": "{map} · Actualizado el {date}",
+  "menu.file": "Archivo",
+  "menu.legal": "Legal",
+  "menu.menu": "Menú",
+  "menu.more": "Más acciones",
+  "menu.privacy": "Política de privacidad",
+  "menu.terms": "Términos de servicio",
+  "notes.centerHint": "Haz clic para centrar en el mapa",
+  "notes.commentPlaceholder": "Añade un comentario…",
+  "notes.comments": "Comentarios",
+  "notes.commentsHint": "Muestra comentarios en línea en el mapa. Arrastra el borde derecho de un comentario seleccionado para cambiar su ancho.",
+  "notes.deleteAria": "Eliminar anotación {label}",
+  "notes.displayAria": "Visualización de marcadores del mapa",
+  "notes.empty": "Todavía no hay anotaciones. Usa la herramienta de marcador para añadir comentarios al mapa.",
+  "notes.heading": "Anotaciones",
+  "notes.labels": "Etiquetas",
+  "notes.labelsHint": "Muestra letras en los marcadores del mapa",
+  "notes.removeHint": "Eliminar este marcador",
+  "notes.toggle": "Notas",
+  "notes.toggleAria": "Mostrar u ocultar anotaciones",
+  "project.untitled": "Proyecto sin título",
+  "pwa.dismissUpdate": "Descartar el aviso de actualización",
+  "pwa.updateAvailable": "Hay una nueva versión de O-Analysis disponible.",
+  "pwa.updateNow": "Actualizar ahora",
+  "rotation.degrees": "{degrees} grados",
+  "rotation.group": "Rotación del lienzo",
+  "rotation.label": "Rotación",
+  "rotation.reset": "Restablecer rotación",
+  "rotation.resetAria": "Restablecer la rotación a 0 grados",
+  "rotation.rotate": "Girar",
+  "save.failed": "Error al guardar automáticamente",
+  "save.saved": "Guardado a las {time}",
+  "save.saving": "Guardando…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "por Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Ajustar el mapa a la pantalla",
+  "status.fitHint": "Ajustar el mapa a la pantalla",
+  "status.legal": "Legal",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Privacidad",
+  "status.terms": "Términos",
+  "status.textSize": "Tamaño del texto",
+  "status.textSizeShort": "Texto",
+  "status.tool": "Herramienta: {tool}",
+  "status.zoomIn": "Acercar",
+  "status.zoomOut": "Alejar",
+  "stroke.color": "Color",
+  "stroke.colorAria": "Color {color}",
+  "stroke.custom": "Color personalizado",
+  "stroke.customHint": "Elige un color personalizado",
+  "stroke.opacity": "Opacidad",
+  "stroke.opacityHint": "Transparencia de líneas y marcadores dibujados",
+  "stroke.useColor": "Usar {color}",
+  "stroke.width": "Ancho",
+  "stroke.widthHint": "Grosor de línea y de marcador",
+  "style.commentTextSize": "Tamaño del texto de los comentarios",
+  "tool.eraser": "Borrador",
+  "tool.eraser.tip": "Haz clic o arrastra sobre trazos y marcadores para eliminarlos.",
+  "tool.eraser.touchTip": "Toca o arrastra sobre trazos y marcadores para eliminarlos.",
+  "tool.gpx": "Ajustar GPX",
+  "tool.gpx.tip": "Haz clic en el recorrido para añadir pines, arrástralos para moverlos y haz clic derecho en un pin para eliminarlo.",
+  "tool.gpx.touchTip": "Toca el recorrido para añadir pines. Mantén pulsado un pin para eliminarlo.",
+  "tool.gpxNeedsFile": "Importa primero un archivo GPX",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Dibujar",
+  "tool.line.tip": "Haz clic y arrastra para dibujar líneas en el mapa.",
+  "tool.line.touchTip": "Arrastra con el dedo para dibujar líneas en el mapa.",
+  "tool.marker": "Marcador",
+  "tool.marker.tip": "Haz clic para colocar un marcador numerado con un comentario.",
+  "tool.marker.touchTip": "Toca para colocar un marcador numerado con un comentario.",
+  "tool.pan": "Mover",
+  "tool.pan.tip": "Arrastra el mapa para desplazarte. Mantén pulsada la barra espaciadora o el botón central para moverlo temporalmente.",
+  "tool.pan.touchTip": "Arrastra con un dedo, o usa dos dedos para mover el mapa en cualquier herramienta.",
+  "tool.select": "Seleccionar",
+  "tool.select.tip": "Haz clic en trazos o marcadores para seleccionarlos. Pulsa Supr para eliminar.",
+  "tool.select.touchTip": "Toca trazos o marcadores para seleccionarlos.",
+  "toolbar.annotations": "Anotaciones",
+  "toolbar.drawingTools": "Herramientas de dibujo",
+  "toolbar.notes": "Notas",
+  "toolbar.strokeSettings": "Ajustes de trazo",
+  "toolbar.style": "Estilo",
+  "toolbar.viewAndStroke": "Vista y ajustes de trazo",
+  "top.dismissError": "Descartar el error",
+  "top.editGpxHint": "Cambia el color, el ancho o la alineación del recorrido",
+  "top.exportDisabled": "Importa una imagen de mapa antes de exportar",
+  "top.exportHint": "Previsualiza y descarga el mapa con dibujos y anotaciones",
+  "top.history": "Historial",
+  "top.importGpxHint": "Importa un archivo GPX para superponer una ruta en el mapa",
+  "top.importImageHint": "Sube una imagen de mapa (PNG, JPG) o suelta un archivo en el lienzo",
+  "top.installApp": "Instalar la app",
+  "top.installHint": "Instala O-Analysis como app de escritorio",
+  "top.new": "Nuevo",
+  "top.newHint": "Limpia el lienzo y empieza de nuevo",
+  "top.open": "Abrir",
+  "top.openHint": "Abre un proyecto guardado ({ext})",
+  "top.projectName": "Nombre del proyecto",
+  "top.projects": "Proyectos",
+  "top.projectsHint": "Cambia entre proyectos guardados",
+  "top.redo": "Rehacer",
+  "top.redoHint": "Rehacer (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Reemplaza la imagen de mapa actual",
+  "top.save": "Guardar",
+  "top.saveDisabled": "Todavía no hay nada que guardar; importa un mapa o añade anotaciones primero",
+  "top.saveHint": "Guarda el proyecto como {ext}",
+  "top.undo": "Deshacer",
+  "top.undoHint": "Deshacer la última acción (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Actualizar la app",
+  "top.updateHint": "Recarga para usar la versión más reciente",
+  "touch.dismissTips": "Descartar los consejos",
+  "touch.tips": "Pellizca para hacer zoom y usa dos dedos para desplazarte. Toca una herramienta y luego el mapa para dibujar o colocar marcadores."
+}
diff --git a/src/locales/fi.json b/src/locales/fi.json
new file mode 100644
index 0000000..79566ba
--- /dev/null
+++ b/src/locales/fi.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Muokkaa GPX:ää",
+  "action.editImage": "Muokkaa kuvaa",
+  "action.export": "Vie",
+  "action.importGpx": "Tuo GPX",
+  "action.importImage": "Tuo kuva",
+  "action.installApp": "Asenna sovellus",
+  "action.newProject": "Uusi projekti",
+  "action.openProject": "Avaa projekti",
+  "action.projects": "Projektit",
+  "action.saveProject": "Tallenna projekti",
+  "action.updateApp": "Päivitä sovellus",
+  "canvas.importHintDrop": "Aloita tuomalla karttakuva tai pudota tiedosto tähän.",
+  "canvas.importHintTouch": "Aloita tuomalla karttakuva.",
+  "canvas.importMap": "Tuo kartta",
+  "canvas.loadingSample": "Ladataan esimerkkiä…",
+  "canvas.noMap": "Karttaa ei ole ladattu",
+  "canvas.openSample": "Avaa esimerkkiprojekti",
+  "color.channel": "{channel}-kanava",
+  "color.channelValue": "{channel}-arvo",
+  "color.custom": "Oma väri",
+  "color.hex": "Hex",
+  "color.hexAria": "Hex-väri",
+  "common.apply": "Käytä",
+  "common.cancel": "Peruuta",
+  "common.close": "Sulje",
+  "common.delete": "Poista",
+  "common.dismiss": "Sulje",
+  "common.errorGeneric": "Jotain meni pieleen",
+  "common.loading": "Ladataan…",
+  "common.rename": "Nimeä uudelleen",
+  "error.body": "O-Analysis kohtasi odottamattoman virheen. Sivun uudelleenlataus auttaa yleensä.",
+  "error.damagedEntry": "Virheellinen {label} projektitiedostossa (kohta {index} on vioittunut)",
+  "error.decodeImage": "Kuvatiedostoa ei voitu lukea",
+  "error.decodeMap": "Karttakuvaa ei voitu lukea",
+  "error.exportTooLarge": "Kartta on liian suuri vietäväksi tällä laitteella",
+  "error.gpxImport": "GPX-tuonti epäonnistui",
+  "error.imageImport": "Kuvan tuonti epäonnistui",
+  "error.imageTooLarge": "Kuva on liian suuri ({size}). Enimmäiskoko on 20 Mt.",
+  "error.invalidEntry": "Virheellinen {label} projektitiedostossa",
+  "error.invalidMap": "Virheellinen karttakuva projektitiedostossa",
+  "error.invalidName": "Virheellinen projektin nimi projektitiedostossa",
+  "error.invalidRotation": "Virheellinen kierto projektitiedostossa",
+  "error.labelAnnotations": "merkinnät",
+  "error.labelDrawings": "piirrokset",
+  "error.labelTracks": "GPX-reitit",
+  "error.loadSample": "Esimerkkiprojektin lataus epäonnistui",
+  "error.noGpxPoints": "GPX-tiedostossa ei ole käytettäviä reittipisteitä",
+  "error.notGpx": "Ei kelvollinen GPX-tiedosto",
+  "error.notImage": "”{name}” ei ole kuvatiedosto",
+  "error.notJson": "Projektitiedosto ei ole kelvollista JSONia",
+  "error.notOurs": "Ei ole O-Analysis-projektitiedosto",
+  "error.notProjectFile": "Ei projektitiedosto – odotettiin {ext}",
+  "error.nothingToSave": "Ei mitään tallennettavaa – tuo kartta tai lisää sisältöä ensin",
+  "error.openProject": "Projektitiedoston avaaminen epäonnistui",
+  "error.projectNotFound": "Projektia ei löytynyt",
+  "error.readImage": "Kuvatiedostoa ei voitu lukea",
+  "error.reload": "Lataa sivu uudelleen",
+  "error.renderExport": "Vientikuvan piirtäminen epäonnistui",
+  "error.sampleNotFound": "Esimerkkiprojektia ei löytynyt",
+  "error.title": "Jotain meni pieleen",
+  "error.unsupportedFile": "Tiedostotyyppi ei ole tuettu: ”{name}”",
+  "error.version": "Projektiversio ei ole tuettu: {version}",
+  "export.download": "Lataa PNG",
+  "export.exporting": "Viedään…",
+  "export.failed": "Vienti epäonnistui – yritä uudelleen",
+  "export.fit": "Sovita",
+  "export.generating": "Luodaan esikatselua…",
+  "export.hint": "Zoomaa vierittämällä · siirrä vetämällä",
+  "export.includeSidebar": "Sisällytä merkintäpaneeli",
+  "export.loadingPreview": "Ladataan esikatselua…",
+  "export.previewAlt": "Viennin esikatselu",
+  "export.resetZoom": "Palauta zoomaus",
+  "export.scaleNotice": "Kartta on suurempi kuin tämä laite voi viedä täydessä koossa, joten PNG-kuva on {percent} % alkuperäisestä resoluutiosta.",
+  "export.sidebarWithComments": "Kommentit näkyvät kartalla – poista paneeli käytöstä välttääksesi päällekkäisyyden.",
+  "export.sidebarWithLabels": "Paneeli listaa jokaisen merkin kirjaimen kommentteineen.",
+  "export.textSize": "Tekstin koko",
+  "export.title": "Vie",
+  "export.zoomIn": "Lähennä",
+  "export.zoomOut": "Loitonna",
+  "gpx.adjustMap": "Säädä kartalla",
+  "gpx.applyCrop": "Käytä rajausta",
+  "gpx.confirm": "Vahvista",
+  "gpx.crop": "Rajaa",
+  "gpx.cropAria": "Rajaa reitti",
+  "gpx.cropError": "Valinnassa on oltava vähintään 2 pistettä.",
+  "gpx.cropTitle": "Rajaa reitti",
+  "gpx.empty": "Ei ladattuja GPX-reittejä.",
+  "gpx.fast": "Nopea (vihreä)",
+  "gpx.highHr": "Korkea syke (kirkkaanpunainen)",
+  "gpx.hr": "Syke",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Viivatyyli",
+  "gpx.lowHr": "Matala syke (tummanpunainen)",
+  "gpx.noTiming": "Tässä GPX-tiedostossa ei ole aikatietoja – rajaa matkan mukaan",
+  "gpx.opacity": "Peittävyys",
+  "gpx.opacityShort": "Peitt.",
+  "gpx.pace": "Vauhti",
+  "gpx.remove": "Poista",
+  "gpx.removeAria": "Poista reitti",
+  "gpx.slow": "Hidas (punainen)",
+  "gpx.solid": "Yhtenäinen",
+  "gpx.strokeWidth": "Viivan leveys",
+  "gpx.tipAdjust": "Siirry karttaan ja vedä ankkuripisteitä",
+  "gpx.tipCrop": "Rajaa reitin alku ja loppu",
+  "gpx.tipRemove": "Poista tämä reitti projektista",
+  "gpx.title": "GPX-reitit",
+  "gpx.toastTapHint": "Napauta reittiä lisätäksesi pisteitä. Poista piste painamalla pitkään.",
+  "gpx.trackColour": "Reitin väri {color}",
+  "gpx.upload": "Lataa",
+  "gpx.width": "Leveys",
+  "language.label": "Kieli",
+  "legal.binding": "Asiakirjan englanninkielinen versio on sitova teksti. Käännökset on tarjottu vain tiedoksi.",
+  "legal.lastUpdated": "Viimeksi päivitetty: {date}",
+  "library.deleteAria": "Poista {name}",
+  "library.empty": "Ei vielä tallennettuja projekteja. Aloita tuomalla kartta.",
+  "library.noMap": "Ei vielä karttaa",
+  "library.open": "Avoin",
+  "library.renameAria": "Nimeä {name} uudelleen",
+  "library.title": "Projektit",
+  "library.updated": "{map} · Päivitetty {date}",
+  "menu.file": "Tiedosto",
+  "menu.legal": "Oikeudellista",
+  "menu.menu": "Valikko",
+  "menu.more": "Lisää toimintoja",
+  "menu.privacy": "Tietosuojaseloste",
+  "menu.terms": "Käyttöehdot",
+  "notes.centerHint": "Napsauta keskittääksesi kartalle",
+  "notes.commentPlaceholder": "Lisää kommentti…",
+  "notes.comments": "Kommentit",
+  "notes.commentsHint": "Näytä kommentit suoraan kartalla. Muuta leveyttä vetämällä valitun kommentin oikeaa reunaa.",
+  "notes.deleteAria": "Poista merkintä {label}",
+  "notes.displayAria": "Karttamerkkien näyttö",
+  "notes.empty": "Ei vielä merkintöjä. Lisää kommentteja kartalle merkkityökalulla.",
+  "notes.heading": "Merkinnät",
+  "notes.labels": "Tunnisteet",
+  "notes.labelsHint": "Näytä kirjaintunnisteet karttamerkeissä",
+  "notes.removeHint": "Poista tämä merkki",
+  "notes.toggle": "Muistiinpanot",
+  "notes.toggleAria": "Näytä tai piilota merkinnät",
+  "project.untitled": "Nimetön projekti",
+  "pwa.dismissUpdate": "Sulje päivitysilmoitus",
+  "pwa.updateAvailable": "O-Analysisin uusi versio on saatavilla.",
+  "pwa.updateNow": "Päivitä nyt",
+  "rotation.degrees": "{degrees} astetta",
+  "rotation.group": "Kartan kierto",
+  "rotation.label": "Kierto",
+  "rotation.reset": "Palauta kierto",
+  "rotation.resetAria": "Palauta kierto 0 asteeseen",
+  "rotation.rotate": "Kierrä",
+  "save.failed": "Automaattinen tallennus epäonnistui",
+  "save.saved": "Tallennettu {time}",
+  "save.saving": "Tallennetaan…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "tekijä Anthony Riley ❤️",
+  "status.fitAria": "Zoomaus {zoom} %. Sovita kartta näytölle",
+  "status.fitHint": "Sovita kartta näytölle",
+  "status.legal": "Oikeudellista",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Tietosuoja",
+  "status.terms": "Ehdot",
+  "status.textSize": "Tekstin koko",
+  "status.textSizeShort": "Teksti",
+  "status.tool": "Työkalu: {tool}",
+  "status.zoomIn": "Lähennä",
+  "status.zoomOut": "Loitonna",
+  "stroke.color": "Väri",
+  "stroke.colorAria": "Väri {color}",
+  "stroke.custom": "Oma väri",
+  "stroke.customHint": "Valitse oma väri",
+  "stroke.opacity": "Peittävyys",
+  "stroke.opacityHint": "Piirrettyjen viivojen ja merkkien läpinäkyvyys",
+  "stroke.useColor": "Käytä väriä {color}",
+  "stroke.width": "Leveys",
+  "stroke.widthHint": "Viivan ja merkin leveys",
+  "style.commentTextSize": "Kommenttien tekstin koko",
+  "tool.eraser": "Pyyhekumi",
+  "tool.eraser.tip": "Poista klikkaamalla tai vetämällä viivojen ja merkkien päältä.",
+  "tool.eraser.touchTip": "Poista napauttamalla tai vetämällä viivojen ja merkkien päältä.",
+  "tool.gpx": "Säädä GPX",
+  "tool.gpx.tip": "Lisää pisteitä klikkaamalla reittiä, siirrä niitä vetämällä ja poista piste oikealla napsautuksella.",
+  "tool.gpx.touchTip": "Lisää pisteitä napauttamalla reittiä. Poista piste painamalla pitkään.",
+  "tool.gpxNeedsFile": "Tuo ensin GPX-tiedosto",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Piirrä",
+  "tool.line.tip": "Piirrä viivoja kartalle klikkaamalla ja vetämällä.",
+  "tool.line.touchTip": "Piirrä viivoja kartalle vetämällä sormella.",
+  "tool.marker": "Merkki",
+  "tool.marker.tip": "Klikkaa asettaaksesi numeroidun merkin kommentilla.",
+  "tool.marker.touchTip": "Napauta asettaaksesi numeroidun merkin kommentilla.",
+  "tool.pan": "Siirrä",
+  "tool.pan.tip": "Vedä karttaa liikkuaksesi. Pidä välilyöntiä tai hiiren keskipainiketta pohjassa tilapäiseen siirtoon.",
+  "tool.pan.touchTip": "Vedä yhdellä sormella tai käytä kahta sormea siirtääksesi kartta millä tahansa työkalulla.",
+  "tool.select": "Valitse",
+  "tool.select.tip": "Valitse viivoja tai merkkejä klikkaamalla. Poista painamalla Delete.",
+  "tool.select.touchTip": "Valitse viivoja tai merkkejä napauttamalla.",
+  "toolbar.annotations": "Merkinnät",
+  "toolbar.drawingTools": "Piirrustustyökalut",
+  "toolbar.notes": "Muistiinpanot",
+  "toolbar.strokeSettings": "Viivan asetukset",
+  "toolbar.style": "Tyyli",
+  "toolbar.viewAndStroke": "Näkymä ja viivan asetukset",
+  "top.dismissError": "Sulje virheilmoitus",
+  "top.editGpxHint": "Muuta reitin väriä, leveyttä tai asemointia",
+  "top.exportDisabled": "Tuo karttakuva ennen viennin aloittamista",
+  "top.exportHint": "Esikatsele ja lataa kartta piirroksineen ja merkintöineen",
+  "top.history": "Historia",
+  "top.importGpxHint": "Tuo GPX-tiedosto reitin piirtämiseksi kartalle",
+  "top.importImageHint": "Lataa karttakuva – PNG, JPG tai pudota tiedosto piirtoalueelle",
+  "top.installApp": "Asenna sovellus",
+  "top.installHint": "Asenna O-Analysis työpöytäsovellukseksi",
+  "top.new": "Uusi",
+  "top.newHint": "Tyhjennä piirtoalue ja aloita alusta",
+  "top.open": "Avaa",
+  "top.openHint": "Avaa tallennettu projekti ({ext})",
+  "top.projectName": "Projektin nimi",
+  "top.projects": "Projektit",
+  "top.projectsHint": "Vaihda tallennettujen projektien välillä",
+  "top.redo": "Tee uudelleen",
+  "top.redoHint": "Tee uudelleen (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Korvaa nykyinen karttakuva",
+  "top.save": "Tallenna",
+  "top.saveDisabled": "Ei vielä tallennettavaa – tuo kartta tai lisää merkintöjä ensin",
+  "top.saveHint": "Tallenna projekti muodossa {ext}",
+  "top.undo": "Kumoa",
+  "top.undoHint": "Kumoa viimeisin toiminto (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Päivitä sovellus",
+  "top.updateHint": "Lataa uudelleen käyttääksesi uusinta versiota",
+  "touch.dismissTips": "Sulje vihjeet",
+  "touch.tips": "Zoomaa nipistämällä, siirrä kahdella sormella. Valitse työkalu napauttamalla ja napauta sitten karttaa piirtääksesi tai asettaaksesi merkkejä."
+}
diff --git a/src/locales/fr.json b/src/locales/fr.json
new file mode 100644
index 0000000..43122e4
--- /dev/null
+++ b/src/locales/fr.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Modifier le GPX",
+  "action.editImage": "Modifier l’image",
+  "action.export": "Exporter",
+  "action.importGpx": "Importer un GPX",
+  "action.importImage": "Importer une image",
+  "action.installApp": "Installer l’application",
+  "action.newProject": "Nouveau projet",
+  "action.openProject": "Ouvrir un projet",
+  "action.projects": "Projets",
+  "action.saveProject": "Enregistrer le projet",
+  "action.updateApp": "Mettre à jour l’application",
+  "canvas.importHintDrop": "Importez une image de carte pour commencer, ou déposez un fichier ici.",
+  "canvas.importHintTouch": "Importez une image de carte pour commencer.",
+  "canvas.importMap": "Importer une carte",
+  "canvas.loadingSample": "Chargement de l’exemple…",
+  "canvas.noMap": "Aucune carte chargée",
+  "canvas.openSample": "Ouvrir le projet d’exemple",
+  "color.channel": "Canal {channel}",
+  "color.channelValue": "Valeur {channel}",
+  "color.custom": "Couleur personnalisée",
+  "color.hex": "Hex",
+  "color.hexAria": "Couleur hexadécimale",
+  "common.apply": "Appliquer",
+  "common.cancel": "Annuler",
+  "common.close": "Fermer",
+  "common.delete": "Supprimer",
+  "common.dismiss": "Ignorer",
+  "common.errorGeneric": "Une erreur s’est produite",
+  "common.loading": "Chargement…",
+  "common.rename": "Renommer",
+  "error.body": "O-Analysis a rencontré une erreur inattendue. Recharger la page règle généralement le problème.",
+  "error.damagedEntry": "{label} invalide dans le fichier du projet (l’entrée {index} est endommagée)",
+  "error.decodeImage": "Impossible de lire le fichier image",
+  "error.decodeMap": "Impossible de lire l’image de la carte",
+  "error.exportTooLarge": "La carte est trop grande pour être exportée sur cet appareil",
+  "error.gpxImport": "Échec de l’importation du GPX",
+  "error.imageImport": "Échec de l’importation de l’image",
+  "error.imageTooLarge": "L’image est trop volumineuse ({size}). La taille maximale est de 20 Mo.",
+  "error.invalidEntry": "{label} invalide dans le fichier du projet",
+  "error.invalidMap": "Image de carte invalide dans le fichier du projet",
+  "error.invalidName": "Nom de projet invalide dans le fichier du projet",
+  "error.invalidRotation": "Rotation invalide dans le fichier du projet",
+  "error.labelAnnotations": "annotations",
+  "error.labelDrawings": "tracés",
+  "error.labelTracks": "traces GPX",
+  "error.loadSample": "Échec du chargement du projet d’exemple",
+  "error.noGpxPoints": "Le fichier GPX ne contient aucun point de trace exploitable",
+  "error.notGpx": "Fichier GPX invalide",
+  "error.notImage": "« {name} » n’est pas un fichier image",
+  "error.notJson": "Le fichier du projet n’est pas un JSON valide",
+  "error.notOurs": "Ce n’est pas un fichier de projet O-Analysis",
+  "error.notProjectFile": "Ce n’est pas un fichier de projet ; {ext} attendu",
+  "error.nothingToSave": "Rien à enregistrer : importez d’abord une carte ou ajoutez du contenu",
+  "error.openProject": "Impossible d’ouvrir le fichier du projet",
+  "error.projectNotFound": "Projet introuvable",
+  "error.readImage": "Impossible de lire le fichier image",
+  "error.reload": "Recharger la page",
+  "error.renderExport": "Impossible de générer l’image d’export",
+  "error.sampleNotFound": "Projet d’exemple introuvable",
+  "error.title": "Une erreur s’est produite",
+  "error.unsupportedFile": "Type de fichier non pris en charge : « {name} »",
+  "error.version": "Version de projet non prise en charge : {version}",
+  "export.download": "Télécharger le PNG",
+  "export.exporting": "Export en cours…",
+  "export.failed": "L’export a échoué, veuillez réessayer",
+  "export.fit": "Ajuster",
+  "export.generating": "Génération de l’aperçu…",
+  "export.hint": "Faites défiler pour zoomer · glissez pour déplacer",
+  "export.includeSidebar": "Inclure le panneau des annotations",
+  "export.loadingPreview": "Chargement de l’aperçu…",
+  "export.previewAlt": "Aperçu de l’export",
+  "export.resetZoom": "Réinitialiser le zoom",
+  "export.scaleNotice": "La carte est plus grande que ce que cet appareil peut exporter en taille réelle ; le PNG sera donc à {percent} % de la résolution d’origine.",
+  "export.sidebarWithComments": "Les commentaires sont affichés sur la carte ; désactivez le panneau pour éviter les doublons.",
+  "export.sidebarWithLabels": "Le panneau liste chaque lettre de repère avec son commentaire.",
+  "export.textSize": "Taille du texte",
+  "export.title": "Exporter",
+  "export.zoomIn": "Zoom avant",
+  "export.zoomOut": "Zoom arrière",
+  "gpx.adjustMap": "Ajuster sur la carte",
+  "gpx.applyCrop": "Appliquer le recadrage",
+  "gpx.confirm": "Confirmer",
+  "gpx.crop": "Recadrer",
+  "gpx.cropAria": "Recadrer la trace",
+  "gpx.cropError": "La sélection doit comporter au moins 2 points.",
+  "gpx.cropTitle": "Recadrer la trace",
+  "gpx.empty": "Aucune trace GPX chargée.",
+  "gpx.fast": "Rapide (vert)",
+  "gpx.highHr": "FC élevée (rouge vif)",
+  "gpx.hr": "FC",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Style de trait",
+  "gpx.lowHr": "FC basse (rouge foncé)",
+  "gpx.noTiming": "Ce GPX ne contient pas de données de temps : recadrez par distance",
+  "gpx.opacity": "Opacité",
+  "gpx.opacityShort": "Opac.",
+  "gpx.pace": "Allure",
+  "gpx.remove": "Retirer",
+  "gpx.removeAria": "Retirer la trace",
+  "gpx.slow": "Lent (rouge)",
+  "gpx.solid": "Plein",
+  "gpx.strokeWidth": "Épaisseur du trait",
+  "gpx.tipAdjust": "Passer à la carte et faire glisser les points d’ancrage",
+  "gpx.tipCrop": "Recadrer le début et la fin de la trace",
+  "gpx.tipRemove": "Retirer cette trace du projet",
+  "gpx.title": "Traces GPX",
+  "gpx.toastTapHint": "Touchez la trace pour ajouter des épingles. Appuyez longuement sur une épingle pour la supprimer.",
+  "gpx.trackColour": "Couleur de la trace {color}",
+  "gpx.upload": "Ajouter",
+  "gpx.width": "Largeur",
+  "language.label": "Langue",
+  "legal.binding": "La version anglaise de ce document fait foi. Les traductions sont fournies à titre indicatif.",
+  "legal.lastUpdated": "Dernière mise à jour : {date}",
+  "library.deleteAria": "Supprimer {name}",
+  "library.empty": "Aucun projet enregistré pour le moment. Importez une carte pour en commencer un.",
+  "library.noMap": "Pas encore de carte",
+  "library.open": "Ouvert",
+  "library.renameAria": "Renommer {name}",
+  "library.title": "Projets",
+  "library.updated": "{map} · Mis à jour le {date}",
+  "menu.file": "Fichier",
+  "menu.legal": "Mentions légales",
+  "menu.menu": "Menu",
+  "menu.more": "Plus d’actions",
+  "menu.privacy": "Politique de confidentialité",
+  "menu.terms": "Conditions d’utilisation",
+  "notes.centerHint": "Cliquez pour centrer sur la carte",
+  "notes.commentPlaceholder": "Ajouter un commentaire…",
+  "notes.comments": "Commentaires",
+  "notes.commentsHint": "Affiche les commentaires directement sur la carte. Faites glisser le bord droit d’un commentaire sélectionné pour changer sa largeur.",
+  "notes.deleteAria": "Supprimer l’annotation {label}",
+  "notes.displayAria": "Affichage des repères de la carte",
+  "notes.empty": "Aucune annotation pour le moment. Utilisez l’outil repère pour ajouter des commentaires sur la carte.",
+  "notes.heading": "Annotations",
+  "notes.labels": "Étiquettes",
+  "notes.labelsHint": "Affiche les lettres sur les repères de la carte",
+  "notes.removeHint": "Supprimer ce repère",
+  "notes.toggle": "Notes",
+  "notes.toggleAria": "Afficher ou masquer les annotations",
+  "project.untitled": "Projet sans titre",
+  "pwa.dismissUpdate": "Ignorer la notification de mise à jour",
+  "pwa.updateAvailable": "Une nouvelle version d’O-Analysis est disponible.",
+  "pwa.updateNow": "Mettre à jour",
+  "rotation.degrees": "{degrees} degrés",
+  "rotation.group": "Rotation de la carte",
+  "rotation.label": "Rotation",
+  "rotation.reset": "Réinitialiser la rotation",
+  "rotation.resetAria": "Réinitialiser la rotation à 0 degré",
+  "rotation.rotate": "Pivoter",
+  "save.failed": "Échec de l’enregistrement automatique",
+  "save.saved": "Enregistré à {time}",
+  "save.saving": "Enregistrement…",
+  "status.coords": "X : {x} Y : {y}",
+  "status.credit": "par Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Ajuster la carte à l’écran",
+  "status.fitHint": "Ajuster la carte à l’écran",
+  "status.legal": "Mentions légales",
+  "status.noCoords": "X : — Y : —",
+  "status.privacy": "Confidentialité",
+  "status.terms": "Conditions",
+  "status.textSize": "Taille du texte",
+  "status.textSizeShort": "Texte",
+  "status.tool": "Outil : {tool}",
+  "status.zoomIn": "Zoom avant",
+  "status.zoomOut": "Zoom arrière",
+  "stroke.color": "Couleur",
+  "stroke.colorAria": "Couleur {color}",
+  "stroke.custom": "Couleur personnalisée",
+  "stroke.customHint": "Choisir une couleur personnalisée",
+  "stroke.opacity": "Opacité",
+  "stroke.opacityHint": "Transparence des traits et repères dessinés",
+  "stroke.useColor": "Utiliser {color}",
+  "stroke.width": "Largeur",
+  "stroke.widthHint": "Épaisseur du trait et du repère",
+  "style.commentTextSize": "Taille du texte des commentaires",
+  "tool.eraser": "Gomme",
+  "tool.eraser.tip": "Cliquez ou glissez sur les tracés et repères pour les supprimer.",
+  "tool.eraser.touchTip": "Touchez ou glissez sur les tracés et repères pour les supprimer.",
+  "tool.gpx": "Ajuster le GPX",
+  "tool.gpx.tip": "Cliquez sur la trace pour ajouter des épingles, glissez-les pour les déplacer, et faites un clic droit sur une épingle pour la supprimer.",
+  "tool.gpx.touchTip": "Touchez la trace pour ajouter des épingles. Appuyez longuement sur une épingle pour la supprimer.",
+  "tool.gpxNeedsFile": "Importez d’abord un fichier GPX",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Tracer",
+  "tool.line.tip": "Cliquez et glissez pour tracer des lignes sur la carte.",
+  "tool.line.touchTip": "Faites glisser le doigt pour tracer des lignes sur la carte.",
+  "tool.marker": "Repère",
+  "tool.marker.tip": "Cliquez pour placer un repère numéroté avec un commentaire.",
+  "tool.marker.touchTip": "Touchez pour placer un repère numéroté avec un commentaire.",
+  "tool.pan": "Déplacer",
+  "tool.pan.tip": "Faites glisser la carte pour vous déplacer. Maintenez la barre d’espace ou le bouton central pour un déplacement temporaire.",
+  "tool.pan.touchTip": "Glissez avec un doigt, ou utilisez deux doigts pour déplacer la carte avec n’importe quel outil.",
+  "tool.select": "Sélectionner",
+  "tool.select.tip": "Cliquez sur des tracés ou des repères pour les sélectionner. Appuyez sur Suppr pour les retirer.",
+  "tool.select.touchTip": "Touchez des tracés ou des repères pour les sélectionner.",
+  "toolbar.annotations": "Annotations",
+  "toolbar.drawingTools": "Outils de dessin",
+  "toolbar.notes": "Notes",
+  "toolbar.strokeSettings": "Réglages du trait",
+  "toolbar.style": "Style",
+  "toolbar.viewAndStroke": "Affichage et réglages du trait",
+  "top.dismissError": "Ignorer l’erreur",
+  "top.editGpxHint": "Modifier la couleur, la largeur ou l’alignement des traces",
+  "top.exportDisabled": "Importez une image de carte avant d’exporter",
+  "top.exportHint": "Prévisualiser et télécharger la carte avec les tracés et annotations",
+  "top.history": "Historique",
+  "top.importGpxHint": "Importer un fichier GPX pour superposer un itinéraire sur la carte",
+  "top.importImageHint": "Charger une image de carte (PNG, JPG) ou déposer un fichier sur le canevas",
+  "top.installApp": "Installer l’application",
+  "top.installHint": "Installer O-Analysis comme application de bureau",
+  "top.new": "Nouveau",
+  "top.newHint": "Vider le canevas et recommencer",
+  "top.open": "Ouvrir",
+  "top.openHint": "Ouvrir un projet enregistré ({ext})",
+  "top.projectName": "Nom du projet",
+  "top.projects": "Projets",
+  "top.projectsHint": "Passer d’un projet enregistré à un autre",
+  "top.redo": "Rétablir",
+  "top.redoHint": "Rétablir (⌘⇧Z / Ctrl+Maj+Z)",
+  "top.replaceImageHint": "Remplacer l’image de carte actuelle",
+  "top.save": "Enregistrer",
+  "top.saveDisabled": "Rien à enregistrer pour le moment : importez une carte ou ajoutez des annotations",
+  "top.saveHint": "Enregistrer le projet au format {ext}",
+  "top.undo": "Annuler",
+  "top.undoHint": "Annuler la dernière action (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Mettre à jour l’application",
+  "top.updateHint": "Recharger pour utiliser la dernière version",
+  "touch.dismissTips": "Ignorer les conseils",
+  "touch.tips": "Pincez pour zoomer, utilisez deux doigts pour déplacer la carte. Touchez un outil puis la carte pour tracer ou placer des repères."
+}
diff --git a/src/locales/nb.json b/src/locales/nb.json
new file mode 100644
index 0000000..96217a3
--- /dev/null
+++ b/src/locales/nb.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Rediger GPX",
+  "action.editImage": "Rediger bilde",
+  "action.export": "Eksporter",
+  "action.importGpx": "Importer GPX",
+  "action.importImage": "Importer bilde",
+  "action.installApp": "Installer appen",
+  "action.newProject": "Nytt prosjekt",
+  "action.openProject": "Åpne prosjekt",
+  "action.projects": "Prosjekter",
+  "action.saveProject": "Lagre prosjekt",
+  "action.updateApp": "Oppdater appen",
+  "canvas.importHintDrop": "Importer et kartbilde for å komme i gang, eller slipp en fil her.",
+  "canvas.importHintTouch": "Importer et kartbilde for å komme i gang.",
+  "canvas.importMap": "Importer kart",
+  "canvas.loadingSample": "Laster eksempel…",
+  "canvas.noMap": "Ingen kart lastet",
+  "canvas.openSample": "Åpne eksempelprosjekt",
+  "color.channel": "{channel}-kanal",
+  "color.channelValue": "{channel}-verdi",
+  "color.custom": "Egendefinert farge",
+  "color.hex": "Hex",
+  "color.hexAria": "Hex-farge",
+  "common.apply": "Bruk",
+  "common.cancel": "Avbryt",
+  "common.close": "Lukk",
+  "common.delete": "Slett",
+  "common.dismiss": "Lukk",
+  "common.errorGeneric": "Noe gikk galt",
+  "common.loading": "Laster…",
+  "common.rename": "Gi nytt navn",
+  "error.body": "O-Analysis møtte en uventet feil. Å laste siden på nytt pleier å løse problemet.",
+  "error.damagedEntry": "Ugyldig {label} i prosjektfilen (oppføring {index} er skadet)",
+  "error.decodeImage": "Bildefilen kunne ikke leses",
+  "error.decodeMap": "Kartbildet kunne ikke leses",
+  "error.exportTooLarge": "Kartet er for stort til å eksporteres på denne enheten",
+  "error.gpxImport": "GPX-importen mislyktes",
+  "error.imageImport": "Bildeimporten mislyktes",
+  "error.imageTooLarge": "Bildet er for stort ({size}). Maksimal størrelse er 20 MB.",
+  "error.invalidEntry": "Ugyldig {label} i prosjektfilen",
+  "error.invalidMap": "Ugyldig kartbilde i prosjektfilen",
+  "error.invalidName": "Ugyldig prosjektnavn i prosjektfilen",
+  "error.invalidRotation": "Ugyldig rotasjon i prosjektfilen",
+  "error.labelAnnotations": "merknader",
+  "error.labelDrawings": "tegninger",
+  "error.labelTracks": "GPX-spor",
+  "error.loadSample": "Eksempelprosjektet kunne ikke lastes",
+  "error.noGpxPoints": "GPX-filen inneholder ingen brukbare sporpunkter",
+  "error.notGpx": "Ikke en gyldig GPX-fil",
+  "error.notImage": "«{name}» er ikke en bildefil",
+  "error.notJson": "Prosjektfilen er ikke gyldig JSON",
+  "error.notOurs": "Ikke en O-Analysis-prosjektfil",
+  "error.notProjectFile": "Ikke en prosjektfil – forventet {ext}",
+  "error.nothingToSave": "Ingenting å lagre – importer et kart eller legg til innhold først",
+  "error.openProject": "Prosjektfilen kunne ikke åpnes",
+  "error.projectNotFound": "Fant ikke prosjektet",
+  "error.readImage": "Bildefilen kunne ikke leses",
+  "error.reload": "Last siden på nytt",
+  "error.renderExport": "Eksportbildet kunne ikke tegnes",
+  "error.sampleNotFound": "Fant ikke eksempelprosjektet",
+  "error.title": "Noe gikk galt",
+  "error.unsupportedFile": "Filtypen støttes ikke: «{name}»",
+  "error.version": "Prosjektversjonen støttes ikke: {version}",
+  "export.download": "Last ned PNG",
+  "export.exporting": "Eksporterer…",
+  "export.failed": "Eksporten mislyktes – prøv igjen",
+  "export.fit": "Tilpass",
+  "export.generating": "Lager forhåndsvisning…",
+  "export.hint": "Rull for å zoome · dra for å flytte",
+  "export.includeSidebar": "Ta med merknadspanelet",
+  "export.loadingPreview": "Laster forhåndsvisning…",
+  "export.previewAlt": "Forhåndsvisning av eksport",
+  "export.resetZoom": "Tilbakestill zoom",
+  "export.scaleNotice": "Kartet er større enn det denne enheten kan eksportere i full størrelse, så PNG-filen blir {percent} % av opprinnelig oppløsning.",
+  "export.sidebarWithComments": "Kommentarene vises på kartet – slå av panelet for å unngå duplisering.",
+  "export.sidebarWithLabels": "Panelet lister opp hver markørbokstav med kommentaren.",
+  "export.textSize": "Tekststørrelse",
+  "export.title": "Eksporter",
+  "export.zoomIn": "Zoom inn",
+  "export.zoomOut": "Zoom ut",
+  "gpx.adjustMap": "Juster på kartet",
+  "gpx.applyCrop": "Bruk beskjæring",
+  "gpx.confirm": "Bekreft",
+  "gpx.crop": "Beskjær",
+  "gpx.cropAria": "Beskjær spor",
+  "gpx.cropError": "Utvalget må inneholde minst 2 punkter.",
+  "gpx.cropTitle": "Beskjær spor",
+  "gpx.empty": "Ingen GPX-spor lastet.",
+  "gpx.fast": "Raskt (grønn)",
+  "gpx.highHr": "Høy puls (lys rød)",
+  "gpx.hr": "Puls",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Linjestil",
+  "gpx.lowHr": "Lav puls (mørk rød)",
+  "gpx.noTiming": "Ingen tidsdata i denne GPX-filen – beskjær etter distanse",
+  "gpx.opacity": "Opasitet",
+  "gpx.opacityShort": "Opas.",
+  "gpx.pace": "Tempo",
+  "gpx.remove": "Fjern",
+  "gpx.removeAria": "Fjern spor",
+  "gpx.slow": "Sakte (rød)",
+  "gpx.solid": "Heltrukket",
+  "gpx.strokeWidth": "Linjebredde",
+  "gpx.tipAdjust": "Bytt til kartet og dra ankerpunktene",
+  "gpx.tipCrop": "Beskjær starten og slutten av sporet",
+  "gpx.tipRemove": "Fjern dette sporet fra prosjektet",
+  "gpx.title": "GPX-spor",
+  "gpx.toastTapHint": "Trykk på sporet for å legge til punkter. Trykk lenge på et punkt for å slette det.",
+  "gpx.trackColour": "Sporfarge {color}",
+  "gpx.upload": "Last opp",
+  "gpx.width": "Bredde",
+  "language.label": "Språk",
+  "legal.binding": "Den engelske versjonen av dokumentet er den bindende teksten. Oversettelsene er laget for din bekvemmelighet.",
+  "legal.lastUpdated": "Sist oppdatert: {date}",
+  "library.deleteAria": "Slett {name}",
+  "library.empty": "Ingen lagrede prosjekter ennå. Importer et kart for å starte ett.",
+  "library.noMap": "Ingen kart ennå",
+  "library.open": "Åpne",
+  "library.renameAria": "Gi nytt navn til {name}",
+  "library.title": "Prosjekter",
+  "library.updated": "{map} · Oppdatert {date}",
+  "menu.file": "Fil",
+  "menu.legal": "Juridisk",
+  "menu.menu": "Meny",
+  "menu.more": "Flere handlinger",
+  "menu.privacy": "Personvernerklæring",
+  "menu.terms": "Vilkår for bruk",
+  "notes.centerHint": "Klikk for å sentrere på kartet",
+  "notes.commentPlaceholder": "Legg til en kommentar…",
+  "notes.comments": "Kommentarer",
+  "notes.commentsHint": "Vis kommentarer direkte på kartet. Dra i høyre kant på en valgt kommentar for å endre bredden.",
+  "notes.deleteAria": "Slett merknad {label}",
+  "notes.displayAria": "Visning av kartmarkører",
+  "notes.empty": "Ingen merknader ennå. Bruk markørverktøyet for å legge til kommentarer på kartet.",
+  "notes.heading": "Merknader",
+  "notes.labels": "Etiketter",
+  "notes.labelsHint": "Vis bokstavetiketter på kartmarkørene",
+  "notes.removeHint": "Fjern denne markøren",
+  "notes.toggle": "Notater",
+  "notes.toggleAria": "Vis eller skjul merknader",
+  "project.untitled": "Uten navn",
+  "pwa.dismissUpdate": "Lukk oppdateringsvarselet",
+  "pwa.updateAvailable": "En ny versjon av O-Analysis er tilgjengelig.",
+  "pwa.updateNow": "Oppdater nå",
+  "rotation.degrees": "{degrees} grader",
+  "rotation.group": "Kartrotasjon",
+  "rotation.label": "Rotasjon",
+  "rotation.reset": "Tilbakestill rotasjon",
+  "rotation.resetAria": "Tilbakestill rotasjonen til 0 grader",
+  "rotation.rotate": "Roter",
+  "save.failed": "Automatisk lagring mislyktes",
+  "save.saved": "Lagret {time}",
+  "save.saving": "Lagrer…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "av Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Tilpass kartet til skjermen",
+  "status.fitHint": "Tilpass kartet til skjermen",
+  "status.legal": "Juridisk",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Personvern",
+  "status.terms": "Vilkår",
+  "status.textSize": "Tekststørrelse",
+  "status.textSizeShort": "Tekst",
+  "status.tool": "Verktøy: {tool}",
+  "status.zoomIn": "Zoom inn",
+  "status.zoomOut": "Zoom ut",
+  "stroke.color": "Farge",
+  "stroke.colorAria": "Farge {color}",
+  "stroke.custom": "Egendefinert farge",
+  "stroke.customHint": "Velg en egendefinert farge",
+  "stroke.opacity": "Opasitet",
+  "stroke.opacityHint": "Gjennomsiktighet for tegnede linjer og markører",
+  "stroke.useColor": "Bruk {color}",
+  "stroke.width": "Bredde",
+  "stroke.widthHint": "Linje- og markørbredde",
+  "style.commentTextSize": "Tekststørrelse for kommentarer",
+  "tool.eraser": "Viskelær",
+  "tool.eraser.tip": "Klikk eller dra over linjer og markører for å fjerne dem.",
+  "tool.eraser.touchTip": "Trykk eller dra over linjer og markører for å fjerne dem.",
+  "tool.gpx": "Juster GPX",
+  "tool.gpx.tip": "Klikk på sporet for å legge til punkter, dra for å flytte dem, og høyreklikk et punkt for å slette det.",
+  "tool.gpx.touchTip": "Trykk på sporet for å legge til punkter. Trykk lenge på et punkt for å slette det.",
+  "tool.gpxNeedsFile": "Importer en GPX-fil først",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Tegn",
+  "tool.line.tip": "Klikk og dra for å tegne linjer på kartet.",
+  "tool.line.touchTip": "Dra fingeren for å tegne linjer på kartet.",
+  "tool.marker": "Markør",
+  "tool.marker.tip": "Klikk for å plassere en nummerert markør med en kommentar.",
+  "tool.marker.touchTip": "Trykk for å plassere en nummerert markør med en kommentar.",
+  "tool.pan": "Flytt",
+  "tool.pan.tip": "Dra kartet for å bevege deg rundt. Hold mellomrom eller midtknappen for midlertidig flytting.",
+  "tool.pan.touchTip": "Dra med ett finger, eller bruk to fingre for å flytte i alle verktøy.",
+  "tool.select": "Velg",
+  "tool.select.tip": "Klikk på linjer eller markører for å velge dem. Trykk Delete for å fjerne.",
+  "tool.select.touchTip": "Trykk på linjer eller markører for å velge dem.",
+  "toolbar.annotations": "Merknader",
+  "toolbar.drawingTools": "Tegneverktøy",
+  "toolbar.notes": "Notater",
+  "toolbar.strokeSettings": "Linjeinnstillinger",
+  "toolbar.style": "Stil",
+  "toolbar.viewAndStroke": "Visning og linjeinnstillinger",
+  "top.dismissError": "Lukk feilmeldingen",
+  "top.editGpxHint": "Endre sporfarge, bredde eller justering",
+  "top.exportDisabled": "Importer et kartbilde før du eksporterer",
+  "top.exportHint": "Forhåndsvis og last ned kartet med tegninger og merknader",
+  "top.history": "Historikk",
+  "top.importGpxHint": "Importer en GPX-fil for å legge en rute over kartet",
+  "top.importImageHint": "Last opp et kartbilde – PNG, JPG, eller slipp en fil på lerretet",
+  "top.installApp": "Installer appen",
+  "top.installHint": "Installer O-Analysis som et skrivebordsprogram",
+  "top.new": "Ny",
+  "top.newHint": "Tøm lerretet og start på nytt",
+  "top.open": "Åpne",
+  "top.openHint": "Åpne et lagret prosjekt ({ext})",
+  "top.projectName": "Prosjektnavn",
+  "top.projects": "Prosjekter",
+  "top.projectsHint": "Bytt mellom lagrede prosjekter",
+  "top.redo": "Gjør om",
+  "top.redoHint": "Gjør om (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Erstatt det gjeldende kartbildet",
+  "top.save": "Lagre",
+  "top.saveDisabled": "Ingenting å lagre ennå – importer et kart eller legg til merknader først",
+  "top.saveHint": "Lagre prosjektet som {ext}",
+  "top.undo": "Angre",
+  "top.undoHint": "Angre siste handling (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Oppdater appen",
+  "top.updateHint": "Last inn på nytt for å bruke den nyeste versjonen",
+  "touch.dismissTips": "Lukk tipsene",
+  "touch.tips": "Klyp for å zoome, bruk to fingre for å flytte. Trykk på et verktøy og deretter på kartet for å tegne eller plassere markører."
+}
diff --git a/src/locales/pt-BR.json b/src/locales/pt-BR.json
new file mode 100644
index 0000000..1287d20
--- /dev/null
+++ b/src/locales/pt-BR.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Editar GPX",
+  "action.editImage": "Editar imagem",
+  "action.export": "Exportar",
+  "action.importGpx": "Importar GPX",
+  "action.importImage": "Importar imagem",
+  "action.installApp": "Instalar o app",
+  "action.newProject": "Novo projeto",
+  "action.openProject": "Abrir projeto",
+  "action.projects": "Projetos",
+  "action.saveProject": "Salvar projeto",
+  "action.updateApp": "Atualizar o app",
+  "canvas.importHintDrop": "Importe uma imagem de mapa para começar, ou solte um arquivo aqui.",
+  "canvas.importHintTouch": "Importe uma imagem de mapa para começar.",
+  "canvas.importMap": "Importar mapa",
+  "canvas.loadingSample": "Carregando exemplo…",
+  "canvas.noMap": "Nenhum mapa carregado",
+  "canvas.openSample": "Abrir projeto de exemplo",
+  "color.channel": "Canal {channel}",
+  "color.channelValue": "Valor de {channel}",
+  "color.custom": "Cor personalizada",
+  "color.hex": "Hex",
+  "color.hexAria": "Cor hexadecimal",
+  "common.apply": "Aplicar",
+  "common.cancel": "Cancelar",
+  "common.close": "Fechar",
+  "common.delete": "Excluir",
+  "common.dismiss": "Dispensar",
+  "common.errorGeneric": "Algo deu errado",
+  "common.loading": "Carregando…",
+  "common.rename": "Renomear",
+  "error.body": "O O-Analysis encontrou um erro inesperado. Recarregar a página geralmente resolve.",
+  "error.damagedEntry": "{label} inválido no arquivo do projeto (o item {index} está danificado)",
+  "error.decodeImage": "Não foi possível ler o arquivo de imagem",
+  "error.decodeMap": "Não foi possível ler a imagem do mapa",
+  "error.exportTooLarge": "O mapa é grande demais para exportar neste dispositivo",
+  "error.gpxImport": "Falha ao importar o GPX",
+  "error.imageImport": "Falha ao importar a imagem",
+  "error.imageTooLarge": "A imagem é grande demais ({size}). O tamanho máximo é 20 MB.",
+  "error.invalidEntry": "{label} inválido no arquivo do projeto",
+  "error.invalidMap": "Imagem de mapa inválida no arquivo do projeto",
+  "error.invalidName": "Nome de projeto inválido no arquivo do projeto",
+  "error.invalidRotation": "Rotação inválida no arquivo do projeto",
+  "error.labelAnnotations": "anotações",
+  "error.labelDrawings": "desenhos",
+  "error.labelTracks": "trajetos GPX",
+  "error.loadSample": "Falha ao carregar o projeto de exemplo",
+  "error.noGpxPoints": "O arquivo GPX não contém pontos de trajeto utilizáveis",
+  "error.notGpx": "Não é um arquivo GPX válido",
+  "error.notImage": "“{name}” não é um arquivo de imagem",
+  "error.notJson": "O arquivo do projeto não é um JSON válido",
+  "error.notOurs": "Não é um arquivo de projeto do O-Analysis",
+  "error.notProjectFile": "Não é um arquivo de projeto; esperado {ext}",
+  "error.nothingToSave": "Nada para salvar – importe um mapa ou adicione conteúdo primeiro",
+  "error.openProject": "Não foi possível abrir o arquivo do projeto",
+  "error.projectNotFound": "Não foi possível encontrar o projeto",
+  "error.readImage": "Não foi possível ler o arquivo de imagem",
+  "error.reload": "Recarregar página",
+  "error.renderExport": "Não foi possível gerar a imagem da exportação",
+  "error.sampleNotFound": "Projeto de exemplo não encontrado",
+  "error.title": "Algo deu errado",
+  "error.unsupportedFile": "Tipo de arquivo não suportado: “{name}”",
+  "error.version": "Versão de projeto não suportada: {version}",
+  "export.download": "Baixar PNG",
+  "export.exporting": "Exportando…",
+  "export.failed": "A exportação falhou – tente novamente",
+  "export.fit": "Ajustar",
+  "export.generating": "Gerando pré-visualização…",
+  "export.hint": "Role para dar zoom · arraste para mover",
+  "export.includeSidebar": "Incluir painel de anotações",
+  "export.loadingPreview": "Carregando pré-visualização…",
+  "export.previewAlt": "Pré-visualização da exportação",
+  "export.resetZoom": "Redefinir zoom",
+  "export.scaleNotice": "O mapa é maior do que este dispositivo consegue exportar em tamanho real, então o PNG ficará com {percent} % da resolução original.",
+  "export.sidebarWithComments": "Os comentários aparecem no mapa – desative o painel para não duplicar.",
+  "export.sidebarWithLabels": "O painel lista cada letra de marcador com o seu comentário.",
+  "export.textSize": "Tamanho do texto",
+  "export.title": "Exportar",
+  "export.zoomIn": "Aproximar",
+  "export.zoomOut": "Afastar",
+  "gpx.adjustMap": "Ajustar no mapa",
+  "gpx.applyCrop": "Aplicar recorte",
+  "gpx.confirm": "Confirmar",
+  "gpx.crop": "Recortar",
+  "gpx.cropAria": "Recortar trajeto",
+  "gpx.cropError": "A seleção deve incluir pelo menos 2 pontos.",
+  "gpx.cropTitle": "Recortar trajeto",
+  "gpx.empty": "Nenhum trajeto GPX carregado.",
+  "gpx.fast": "Rápido (verde)",
+  "gpx.highHr": "FC alta (vermelho vivo)",
+  "gpx.hr": "FC",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Estilo de linha",
+  "gpx.lowHr": "FC baixa (vermelho escuro)",
+  "gpx.noTiming": "Este GPX não tem dados de tempo – recorte por distância",
+  "gpx.opacity": "Opacidade",
+  "gpx.opacityShort": "Opac.",
+  "gpx.pace": "Ritmo",
+  "gpx.remove": "Remover",
+  "gpx.removeAria": "Remover trajeto",
+  "gpx.slow": "Lento (vermelho)",
+  "gpx.solid": "Sólido",
+  "gpx.strokeWidth": "Espessura da linha",
+  "gpx.tipAdjust": "Mude para o mapa e arraste os pinos de ancoragem",
+  "gpx.tipCrop": "Recorte o início e o fim do trajeto",
+  "gpx.tipRemove": "Remover este trajeto do projeto",
+  "gpx.title": "Trajetos GPX",
+  "gpx.toastTapHint": "Toque no trajeto para adicionar pinos. Pressione e segure um pino para excluí-lo.",
+  "gpx.trackColour": "Cor do trajeto {color}",
+  "gpx.upload": "Enviar",
+  "gpx.width": "Largura",
+  "language.label": "Idioma",
+  "legal.binding": "A versão em inglês deste documento é o texto vinculante. As traduções são oferecidas apenas para sua conveniência.",
+  "legal.lastUpdated": "Última atualização: {date}",
+  "library.deleteAria": "Excluir {name}",
+  "library.empty": "Nenhum projeto salvo ainda. Importe um mapa para começar um.",
+  "library.noMap": "Sem mapa ainda",
+  "library.open": "Aberto",
+  "library.renameAria": "Renomear {name}",
+  "library.title": "Projetos",
+  "library.updated": "{map} · Atualizado em {date}",
+  "menu.file": "Arquivo",
+  "menu.legal": "Jurídico",
+  "menu.menu": "Menu",
+  "menu.more": "Mais ações",
+  "menu.privacy": "Política de privacidade",
+  "menu.terms": "Termos de uso",
+  "notes.centerHint": "Clique para centralizar no mapa",
+  "notes.commentPlaceholder": "Adicione um comentário…",
+  "notes.comments": "Comentários",
+  "notes.commentsHint": "Mostra comentários diretamente no mapa. Arraste a borda direita de um comentário selecionado para mudar a largura.",
+  "notes.deleteAria": "Excluir anotação {label}",
+  "notes.displayAria": "Exibição dos marcadores do mapa",
+  "notes.empty": "Nenhuma anotação ainda. Use a ferramenta de marcador para adicionar comentários ao mapa.",
+  "notes.heading": "Anotações",
+  "notes.labels": "Rótulos",
+  "notes.labelsHint": "Mostra letras nos marcadores do mapa",
+  "notes.removeHint": "Remover este marcador",
+  "notes.toggle": "Notas",
+  "notes.toggleAria": "Mostrar ou ocultar anotações",
+  "project.untitled": "Projeto sem título",
+  "pwa.dismissUpdate": "Dispensar aviso de atualização",
+  "pwa.updateAvailable": "Uma nova versão do O-Analysis está disponível.",
+  "pwa.updateNow": "Atualizar agora",
+  "rotation.degrees": "{degrees} graus",
+  "rotation.group": "Rotação da tela",
+  "rotation.label": "Rotação",
+  "rotation.reset": "Redefinir rotação",
+  "rotation.resetAria": "Redefinir a rotação para 0 graus",
+  "rotation.rotate": "Girar",
+  "save.failed": "Falha no salvamento automático",
+  "save.saved": "Salvo às {time}",
+  "save.saving": "Salvando…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "por Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Ajustar o mapa à tela",
+  "status.fitHint": "Ajustar o mapa à tela",
+  "status.legal": "Jurídico",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Privacidade",
+  "status.terms": "Termos",
+  "status.textSize": "Tamanho do texto",
+  "status.textSizeShort": "Texto",
+  "status.tool": "Ferramenta: {tool}",
+  "status.zoomIn": "Aproximar",
+  "status.zoomOut": "Afastar",
+  "stroke.color": "Cor",
+  "stroke.colorAria": "Cor {color}",
+  "stroke.custom": "Cor personalizada",
+  "stroke.customHint": "Escolher uma cor personalizada",
+  "stroke.opacity": "Opacidade",
+  "stroke.opacityHint": "Transparência das linhas e marcadores desenhados",
+  "stroke.useColor": "Usar {color}",
+  "stroke.width": "Largura",
+  "stroke.widthHint": "Espessura da linha e do marcador",
+  "style.commentTextSize": "Tamanho do texto dos comentários",
+  "tool.eraser": "Borracha",
+  "tool.eraser.tip": "Clique ou arraste sobre trajetos e marcadores para removê-los.",
+  "tool.eraser.touchTip": "Toque ou arraste sobre trajetos e marcadores para removê-los.",
+  "tool.gpx": "Ajustar GPX",
+  "tool.gpx.tip": "Clique no trajeto para adicionar pinos, arraste-os para mover e clique com o botão direito em um pino para excluí-lo.",
+  "tool.gpx.touchTip": "Toque no trajeto para adicionar pinos. Pressione e segure um pino para excluí-lo.",
+  "tool.gpxNeedsFile": "Importe um arquivo GPX primeiro",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Desenhar",
+  "tool.line.tip": "Clique e arraste para desenhar linhas no mapa.",
+  "tool.line.touchTip": "Arraste o dedo para desenhar linhas no mapa.",
+  "tool.marker": "Marcador",
+  "tool.marker.tip": "Clique para colocar um marcador numerado com um comentário.",
+  "tool.marker.touchTip": "Toque para colocar um marcador numerado com um comentário.",
+  "tool.pan": "Mover",
+  "tool.pan.tip": "Arraste o mapa para se movimentar. Segure a barra de espaço ou o botão do meio para mover temporariamente.",
+  "tool.pan.touchTip": "Arraste com um dedo, ou use dois dedos para mover o mapa em qualquer ferramenta.",
+  "tool.select": "Selecionar",
+  "tool.select.tip": "Clique em trajetos ou marcadores para selecioná-los. Pressione Delete para remover.",
+  "tool.select.touchTip": "Toque em trajetos ou marcadores para selecioná-los.",
+  "toolbar.annotations": "Anotações",
+  "toolbar.drawingTools": "Ferramentas de desenho",
+  "toolbar.notes": "Notas",
+  "toolbar.strokeSettings": "Configurações de traço",
+  "toolbar.style": "Estilo",
+  "toolbar.viewAndStroke": "Visualização e configurações de traço",
+  "top.dismissError": "Dispensar erro",
+  "top.editGpxHint": "Mude a cor, a largura ou o alinhamento dos trajetos",
+  "top.exportDisabled": "Importe uma imagem de mapa antes de exportar",
+  "top.exportHint": "Pré-visualize e baixe o mapa com desenhos e anotações",
+  "top.history": "Histórico",
+  "top.importGpxHint": "Importe um arquivo GPX para sobrepor uma rota no mapa",
+  "top.importImageHint": "Envie uma imagem de mapa (PNG, JPG) ou solte um arquivo na tela",
+  "top.installApp": "Instalar o app",
+  "top.installHint": "Instale o O-Analysis como aplicativo de desktop",
+  "top.new": "Novo",
+  "top.newHint": "Limpe a tela e comece do zero",
+  "top.open": "Abrir",
+  "top.openHint": "Abra um projeto salvo ({ext})",
+  "top.projectName": "Nome do projeto",
+  "top.projects": "Projetos",
+  "top.projectsHint": "Alterne entre projetos salvos",
+  "top.redo": "Refazer",
+  "top.redoHint": "Refazer (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Substituir a imagem de mapa atual",
+  "top.save": "Salvar",
+  "top.saveDisabled": "Nada para salvar ainda – importe um mapa ou adicione anotações primeiro",
+  "top.saveHint": "Salvar o projeto como {ext}",
+  "top.undo": "Desfazer",
+  "top.undoHint": "Desfazer a última ação (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Atualizar o app",
+  "top.updateHint": "Recarregue para usar a versão mais recente",
+  "touch.dismissTips": "Dispensar as dicas",
+  "touch.tips": "Pince para dar zoom, use dois dedos para mover. Toque em uma ferramenta e depois no mapa para desenhar ou colocar marcadores."
+}
diff --git a/src/locales/pt-PT.json b/src/locales/pt-PT.json
new file mode 100644
index 0000000..5c6a144
--- /dev/null
+++ b/src/locales/pt-PT.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Editar GPX",
+  "action.editImage": "Editar imagem",
+  "action.export": "Exportar",
+  "action.importGpx": "Importar GPX",
+  "action.importImage": "Importar imagem",
+  "action.installApp": "Instalar a aplicação",
+  "action.newProject": "Novo projeto",
+  "action.openProject": "Abrir projeto",
+  "action.projects": "Projetos",
+  "action.saveProject": "Guardar projeto",
+  "action.updateApp": "Atualizar a aplicação",
+  "canvas.importHintDrop": "Importe uma imagem de mapa para começar, ou arraste um ficheiro para aqui.",
+  "canvas.importHintTouch": "Importe uma imagem de mapa para começar.",
+  "canvas.importMap": "Importar mapa",
+  "canvas.loadingSample": "A carregar o exemplo…",
+  "canvas.noMap": "Nenhum mapa carregado",
+  "canvas.openSample": "Abrir projeto de exemplo",
+  "color.channel": "Canal {channel}",
+  "color.channelValue": "Valor de {channel}",
+  "color.custom": "Cor personalizada",
+  "color.hex": "Hex",
+  "color.hexAria": "Cor hexadecimal",
+  "common.apply": "Aplicar",
+  "common.cancel": "Cancelar",
+  "common.close": "Fechar",
+  "common.delete": "Eliminar",
+  "common.dismiss": "Dispensar",
+  "common.errorGeneric": "Algo correu mal",
+  "common.loading": "A carregar…",
+  "common.rename": "Mudar o nome",
+  "error.body": "O O-Analysis encontrou um erro inesperado. Recarregar a página costuma resolver.",
+  "error.damagedEntry": "{label} inválido no ficheiro do projeto (o item {index} está danificado)",
+  "error.decodeImage": "Não foi possível ler o ficheiro de imagem",
+  "error.decodeMap": "Não foi possível ler a imagem do mapa",
+  "error.exportTooLarge": "O mapa é demasiado grande para exportar neste dispositivo",
+  "error.gpxImport": "Falha ao importar o GPX",
+  "error.imageImport": "Falha ao importar a imagem",
+  "error.imageTooLarge": "A imagem é demasiado grande ({size}). O tamanho máximo é 20 MB.",
+  "error.invalidEntry": "{label} inválido no ficheiro do projeto",
+  "error.invalidMap": "Imagem de mapa inválida no ficheiro do projeto",
+  "error.invalidName": "Nome de projeto inválido no ficheiro do projeto",
+  "error.invalidRotation": "Rotação inválida no ficheiro do projeto",
+  "error.labelAnnotations": "anotações",
+  "error.labelDrawings": "desenhos",
+  "error.labelTracks": "percursos GPX",
+  "error.loadSample": "Falha ao carregar o projeto de exemplo",
+  "error.noGpxPoints": "O ficheiro GPX não contém pontos de percurso utilizáveis",
+  "error.notGpx": "Não é um ficheiro GPX válido",
+  "error.notImage": "«{name}» não é um ficheiro de imagem",
+  "error.notJson": "O ficheiro do projeto não é um JSON válido",
+  "error.notOurs": "Não é um ficheiro de projeto do O-Analysis",
+  "error.notProjectFile": "Não é um ficheiro de projeto; esperado {ext}",
+  "error.nothingToSave": "Nada para guardar – importe um mapa ou adicione conteúdo primeiro",
+  "error.openProject": "Não foi possível abrir o ficheiro do projeto",
+  "error.projectNotFound": "Não foi possível encontrar o projeto",
+  "error.readImage": "Não foi possível ler o ficheiro de imagem",
+  "error.reload": "Recarregar página",
+  "error.renderExport": "Não foi possível gerar a imagem da exportação",
+  "error.sampleNotFound": "Projeto de exemplo não encontrado",
+  "error.title": "Algo correu mal",
+  "error.unsupportedFile": "Tipo de ficheiro não suportado: «{name}»",
+  "error.version": "Versão de projeto não suportada: {version}",
+  "export.download": "Transferir PNG",
+  "export.exporting": "A exportar…",
+  "export.failed": "A exportação falhou – tente novamente",
+  "export.fit": "Ajustar",
+  "export.generating": "A gerar pré-visualização…",
+  "export.hint": "Deslize para ampliar · arraste para mover",
+  "export.includeSidebar": "Incluir painel de anotações",
+  "export.loadingPreview": "A carregar pré-visualização…",
+  "export.previewAlt": "Pré-visualização da exportação",
+  "export.resetZoom": "Repor zoom",
+  "export.scaleNotice": "O mapa é maior do que este dispositivo consegue exportar em tamanho real, por isso o PNG ficará com {percent} % da resolução original.",
+  "export.sidebarWithComments": "Os comentários aparecem no mapa – desative o painel para não duplicar.",
+  "export.sidebarWithLabels": "O painel lista cada letra de marcador com o respetivo comentário.",
+  "export.textSize": "Tamanho do texto",
+  "export.title": "Exportar",
+  "export.zoomIn": "Ampliar",
+  "export.zoomOut": "Reduzir",
+  "gpx.adjustMap": "Ajustar no mapa",
+  "gpx.applyCrop": "Aplicar recorte",
+  "gpx.confirm": "Confirmar",
+  "gpx.crop": "Recortar",
+  "gpx.cropAria": "Recortar percurso",
+  "gpx.cropError": "A seleção deve incluir pelo menos 2 pontos.",
+  "gpx.cropTitle": "Recortar percurso",
+  "gpx.empty": "Nenhum percurso GPX carregado.",
+  "gpx.fast": "Rápido (verde)",
+  "gpx.highHr": "FC alta (vermelho vivo)",
+  "gpx.hr": "FC",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Estilo de linha",
+  "gpx.lowHr": "FC baixa (vermelho escuro)",
+  "gpx.noTiming": "Este GPX não tem dados de tempo – recorte por distância",
+  "gpx.opacity": "Opacidade",
+  "gpx.opacityShort": "Opac.",
+  "gpx.pace": "Ritmo",
+  "gpx.remove": "Remover",
+  "gpx.removeAria": "Remover percurso",
+  "gpx.slow": "Lento (vermelho)",
+  "gpx.solid": "Contínuo",
+  "gpx.strokeWidth": "Espessura da linha",
+  "gpx.tipAdjust": "Mude para o mapa e arraste os alfinetes de ancoragem",
+  "gpx.tipCrop": "Recorte o início e o fim do percurso",
+  "gpx.tipRemove": "Remover este percurso do projeto",
+  "gpx.title": "Percursos GPX",
+  "gpx.toastTapHint": "Toque no percurso para adicionar alfinetes. Mantenha premido um alfinete para o eliminar.",
+  "gpx.trackColour": "Cor do percurso {color}",
+  "gpx.upload": "Carregar",
+  "gpx.width": "Largura",
+  "language.label": "Idioma",
+  "legal.binding": "A versão inglesa deste documento é o texto vinculativo. As traduções são disponibilizadas apenas para conveniência.",
+  "legal.lastUpdated": "Última atualização: {date}",
+  "library.deleteAria": "Eliminar {name}",
+  "library.empty": "Ainda não há projetos guardados. Importe um mapa para começar um.",
+  "library.noMap": "Sem mapa ainda",
+  "library.open": "Aberto",
+  "library.renameAria": "Mudar o nome de {name}",
+  "library.title": "Projetos",
+  "library.updated": "{map} · Atualizado em {date}",
+  "menu.file": "Ficheiro",
+  "menu.legal": "Jurídico",
+  "menu.menu": "Menu",
+  "menu.more": "Mais ações",
+  "menu.privacy": "Política de privacidade",
+  "menu.terms": "Termos de utilização",
+  "notes.centerHint": "Clique para centrar no mapa",
+  "notes.commentPlaceholder": "Adicione um comentário…",
+  "notes.comments": "Comentários",
+  "notes.commentsHint": "Mostra os comentários diretamente no mapa. Arraste a borda direita de um comentário selecionado para alterar a largura.",
+  "notes.deleteAria": "Eliminar anotação {label}",
+  "notes.displayAria": "Visualização dos marcadores do mapa",
+  "notes.empty": "Ainda não há anotações. Use a ferramenta de marcador para adicionar comentários ao mapa.",
+  "notes.heading": "Anotações",
+  "notes.labels": "Etiquetas",
+  "notes.labelsHint": "Mostra letras nos marcadores do mapa",
+  "notes.removeHint": "Remover este marcador",
+  "notes.toggle": "Notas",
+  "notes.toggleAria": "Mostrar ou ocultar anotações",
+  "project.untitled": "Projeto sem título",
+  "pwa.dismissUpdate": "Dispensar aviso de atualização",
+  "pwa.updateAvailable": "Está disponível uma nova versão do O-Analysis.",
+  "pwa.updateNow": "Atualizar agora",
+  "rotation.degrees": "{degrees} graus",
+  "rotation.group": "Rotação do ecrã",
+  "rotation.label": "Rotação",
+  "rotation.reset": "Repor rotação",
+  "rotation.resetAria": "Repor a rotação para 0 graus",
+  "rotation.rotate": "Rodar",
+  "save.failed": "Falha na gravação automática",
+  "save.saved": "Guardado às {time}",
+  "save.saving": "A guardar…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "por Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Ajustar o mapa ao ecrã",
+  "status.fitHint": "Ajustar o mapa ao ecrã",
+  "status.legal": "Jurídico",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Privacidade",
+  "status.terms": "Termos",
+  "status.textSize": "Tamanho do texto",
+  "status.textSizeShort": "Texto",
+  "status.tool": "Ferramenta: {tool}",
+  "status.zoomIn": "Ampliar",
+  "status.zoomOut": "Reduzir",
+  "stroke.color": "Cor",
+  "stroke.colorAria": "Cor {color}",
+  "stroke.custom": "Cor personalizada",
+  "stroke.customHint": "Escolher uma cor personalizada",
+  "stroke.opacity": "Opacidade",
+  "stroke.opacityHint": "Transparência das linhas e marcadores desenhados",
+  "stroke.useColor": "Usar {color}",
+  "stroke.width": "Largura",
+  "stroke.widthHint": "Espessura da linha e do marcador",
+  "style.commentTextSize": "Tamanho do texto dos comentários",
+  "tool.eraser": "Borracha",
+  "tool.eraser.tip": "Clique ou arraste sobre percursos e marcadores para os remover.",
+  "tool.eraser.touchTip": "Toque ou arraste sobre percursos e marcadores para os remover.",
+  "tool.gpx": "Ajustar GPX",
+  "tool.gpx.tip": "Clique no percurso para adicionar alfinetes, arraste-os para os mover e clique com o botão direito num alfinete para o eliminar.",
+  "tool.gpx.touchTip": "Toque no percurso para adicionar alfinetes. Mantenha premido um alfinete para o eliminar.",
+  "tool.gpxNeedsFile": "Importe primeiro um ficheiro GPX",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Desenhar",
+  "tool.line.tip": "Clique e arraste para desenhar linhas no mapa.",
+  "tool.line.touchTip": "Arraste o dedo para desenhar linhas no mapa.",
+  "tool.marker": "Marcador",
+  "tool.marker.tip": "Clique para colocar um marcador numerado com um comentário.",
+  "tool.marker.touchTip": "Toque para colocar um marcador numerado com um comentário.",
+  "tool.pan": "Mover",
+  "tool.pan.tip": "Arraste o mapa para se deslocar. Mantenha premida a barra de espaço ou o botão do meio para mover temporariamente.",
+  "tool.pan.touchTip": "Arraste com um dedo, ou use dois dedos para mover o mapa em qualquer ferramenta.",
+  "tool.select": "Selecionar",
+  "tool.select.tip": "Clique em percursos ou marcadores para os selecionar. Prima Delete para remover.",
+  "tool.select.touchTip": "Toque em percursos ou marcadores para os selecionar.",
+  "toolbar.annotations": "Anotações",
+  "toolbar.drawingTools": "Ferramentas de desenho",
+  "toolbar.notes": "Notas",
+  "toolbar.strokeSettings": "Definições do traço",
+  "toolbar.style": "Estilo",
+  "toolbar.viewAndStroke": "Visualização e definições do traço",
+  "top.dismissError": "Dispensar erro",
+  "top.editGpxHint": "Altere a cor, a largura ou o alinhamento dos percursos",
+  "top.exportDisabled": "Importe uma imagem de mapa antes de exportar",
+  "top.exportHint": "Pré-visualize e transfira o mapa com desenhos e anotações",
+  "top.history": "Histórico",
+  "top.importGpxHint": "Importe um ficheiro GPX para sobrepor um percurso no mapa",
+  "top.importImageHint": "Carregue uma imagem de mapa (PNG, JPG) ou arraste um ficheiro para a área de desenho",
+  "top.installApp": "Instalar a aplicação",
+  "top.installHint": "Instale o O-Analysis como aplicação de ambiente de trabalho",
+  "top.new": "Novo",
+  "top.newHint": "Limpe a área de desenho e comece de novo",
+  "top.open": "Abrir",
+  "top.openHint": "Abra um projeto guardado ({ext})",
+  "top.projectName": "Nome do projeto",
+  "top.projects": "Projetos",
+  "top.projectsHint": "Alterne entre projetos guardados",
+  "top.redo": "Refazer",
+  "top.redoHint": "Refazer (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Substituir a imagem de mapa atual",
+  "top.save": "Guardar",
+  "top.saveDisabled": "Nada para guardar ainda – importe um mapa ou adicione anotações primeiro",
+  "top.saveHint": "Guardar o projeto como {ext}",
+  "top.undo": "Anular",
+  "top.undoHint": "Anular a última ação (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Atualizar a aplicação",
+  "top.updateHint": "Recarregue para usar a versão mais recente",
+  "touch.dismissTips": "Dispensar as sugestões",
+  "touch.tips": "Faça um pinça para ampliar, use dois dedos para mover. Toque numa ferramenta e depois no mapa para desenhar ou colocar marcadores."
+}
diff --git a/src/locales/sv.json b/src/locales/sv.json
new file mode 100644
index 0000000..e710480
--- /dev/null
+++ b/src/locales/sv.json
@@ -0,0 +1,232 @@
+{
+  "action.editGpx": "Redigera GPX",
+  "action.editImage": "Redigera bild",
+  "action.export": "Exportera",
+  "action.importGpx": "Importera GPX",
+  "action.importImage": "Importera bild",
+  "action.installApp": "Installera appen",
+  "action.newProject": "Nytt projekt",
+  "action.openProject": "Öppna projekt",
+  "action.projects": "Projekt",
+  "action.saveProject": "Spara projekt",
+  "action.updateApp": "Uppdatera appen",
+  "canvas.importHintDrop": "Importera en kartbild för att komma igång, eller släpp en fil här.",
+  "canvas.importHintTouch": "Importera en kartbild för att komma igång.",
+  "canvas.importMap": "Importera karta",
+  "canvas.loadingSample": "Läser in exempel…",
+  "canvas.noMap": "Ingen karta inläst",
+  "canvas.openSample": "Öppna exempelprojekt",
+  "color.channel": "{channel}-kanal",
+  "color.channelValue": "{channel}-värde",
+  "color.custom": "Egen färg",
+  "color.hex": "Hex",
+  "color.hexAria": "Hex-färg",
+  "common.apply": "Använd",
+  "common.cancel": "Avbryt",
+  "common.close": "Stäng",
+  "common.delete": "Ta bort",
+  "common.dismiss": "Stäng",
+  "common.errorGeneric": "Något gick fel",
+  "common.loading": "Laddar…",
+  "common.rename": "Byt namn",
+  "error.body": "O-Analysis stötte på ett oväntat fel. Att ladda om sidan brukar lösa det.",
+  "error.damagedEntry": "Ogiltig {label} i projektfilen (post {index} är skadad)",
+  "error.decodeImage": "Bildfilen kunde inte läsas in",
+  "error.decodeMap": "Kartbilden kunde inte läsas in",
+  "error.exportTooLarge": "Kartan är för stor för att exporteras på den här enheten",
+  "error.gpxImport": "GPX-importen misslyckades",
+  "error.imageImport": "Bildimporten misslyckades",
+  "error.imageTooLarge": "Bilden är för stor ({size}). Maxstorleken är 20 MB.",
+  "error.invalidEntry": "Ogiltig {label} i projektfilen",
+  "error.invalidMap": "Ogiltig kartbild i projektfilen",
+  "error.invalidName": "Ogiltigt projektnamn i projektfilen",
+  "error.invalidRotation": "Ogiltig rotation i projektfilen",
+  "error.labelAnnotations": "annoteringar",
+  "error.labelDrawings": "ritningar",
+  "error.labelTracks": "GPX-spår",
+  "error.loadSample": "Exempelprojektet kunde inte läsas in",
+  "error.noGpxPoints": "GPX-filen innehåller inga användbara spårpunkter",
+  "error.notGpx": "Inte en giltig GPX-fil",
+  "error.notImage": "”{name}” är inte en bildfil",
+  "error.notJson": "Projektfilen är inte giltig JSON",
+  "error.notOurs": "Inte en O-Analysis-projektfil",
+  "error.notProjectFile": "Inte en projektfil – förväntade {ext}",
+  "error.nothingToSave": "Inget att spara – importera en karta eller lägg till innehåll först",
+  "error.openProject": "Projektfilen kunde inte öppnas",
+  "error.projectNotFound": "Projektet kunde inte hittas",
+  "error.readImage": "Bildfilen kunde inte läsas",
+  "error.reload": "Ladda om sidan",
+  "error.renderExport": "Exportbilden kunde inte renderas",
+  "error.sampleNotFound": "Exempelprojektet hittades inte",
+  "error.title": "Något gick fel",
+  "error.unsupportedFile": "Filtypen stöds inte: ”{name}”",
+  "error.version": "Projektversionen stöds inte: {version}",
+  "export.download": "Ladda ner PNG",
+  "export.exporting": "Exporterar…",
+  "export.failed": "Exporten misslyckades – försök igen",
+  "export.fit": "Anpassa",
+  "export.generating": "Skapar förhandsvisning…",
+  "export.hint": "Scrolla för att zooma · dra för att panorera",
+  "export.includeSidebar": "Inkludera annoteringspanel",
+  "export.loadingPreview": "Läser in förhandsvisning…",
+  "export.previewAlt": "Förhandsvisning av export",
+  "export.resetZoom": "Återställ zoom",
+  "export.scaleNotice": "Kartan är större än vad den här enheten kan exportera i full storlek, så PNG-filen blir {percent} % av originalupplösningen.",
+  "export.sidebarWithComments": "Kommentarerna visas på kartan – stäng av panelen för att undvika dubbletter.",
+  "export.sidebarWithLabels": "Panelen listar varje markörbokstav med sin kommentar.",
+  "export.textSize": "Textstorlek",
+  "export.title": "Exportera",
+  "export.zoomIn": "Zooma in",
+  "export.zoomOut": "Zooma ut",
+  "gpx.adjustMap": "Justera på kartan",
+  "gpx.applyCrop": "Tillämpa beskärning",
+  "gpx.confirm": "Bekräfta",
+  "gpx.crop": "Beskär",
+  "gpx.cropAria": "Beskär spår",
+  "gpx.cropError": "Markeringen måste innehålla minst 2 punkter.",
+  "gpx.cropTitle": "Beskär spår",
+  "gpx.empty": "Inga GPX-spår inlästa.",
+  "gpx.fast": "Snabb (grön)",
+  "gpx.highHr": "Hög puls (ljusröd)",
+  "gpx.hr": "Puls",
+  "gpx.km": "{value} km",
+  "gpx.lineStyleAria": "Linjestil",
+  "gpx.lowHr": "Låg puls (mörkröd)",
+  "gpx.noTiming": "Ingen tidsdata i den här GPX-filen – beskär efter sträcka",
+  "gpx.opacity": "Opacitet",
+  "gpx.opacityShort": "Opak.",
+  "gpx.pace": "Tempo",
+  "gpx.remove": "Ta bort",
+  "gpx.removeAria": "Ta bort spår",
+  "gpx.slow": "Långsam (röd)",
+  "gpx.solid": "Heldragen",
+  "gpx.strokeWidth": "Linjebredd",
+  "gpx.tipAdjust": "Byt till kartan och dra ankarpunkterna",
+  "gpx.tipCrop": "Beskär spårets början och slut",
+  "gpx.tipRemove": "Ta bort spåret från projektet",
+  "gpx.title": "GPX-spår",
+  "gpx.toastTapHint": "Tryck på spåret för att lägga till punkter. Tryck länge på en punkt för att ta bort den.",
+  "gpx.trackColour": "Spårfärg {color}",
+  "gpx.upload": "Ladda upp",
+  "gpx.width": "Bredd",
+  "language.label": "Språk",
+  "legal.binding": "Den engelska versionen av dokumentet är den bindande texten. Översättningarna tillhandahålls för bekvämlighets skull.",
+  "legal.lastUpdated": "Senast uppdaterad: {date}",
+  "library.deleteAria": "Ta bort {name}",
+  "library.empty": "Inga sparade projekt än. Importera en karta för att börja.",
+  "library.noMap": "Ingen karta än",
+  "library.open": "Öppna",
+  "library.renameAria": "Byt namn på {name}",
+  "library.title": "Projekt",
+  "library.updated": "{map} · Uppdaterad {date}",
+  "menu.file": "Fil",
+  "menu.legal": "Juridiskt",
+  "menu.menu": "Meny",
+  "menu.more": "Fler åtgärder",
+  "menu.privacy": "Integritetspolicy",
+  "menu.terms": "Användarvillkor",
+  "notes.centerHint": "Klicka för att centrera på kartan",
+  "notes.commentPlaceholder": "Lägg till en kommentar…",
+  "notes.comments": "Kommentarer",
+  "notes.commentsHint": "Visa kommentarer direkt på kartan. Dra i den högra kanten på en vald kommentar för att ändra bredden.",
+  "notes.deleteAria": "Ta bort annotering {label}",
+  "notes.displayAria": "Visning av kartmarkörer",
+  "notes.empty": "Inga annoteringar än. Använd markörverktyget för att lägga till kommentarer på kartan.",
+  "notes.heading": "Annoteringar",
+  "notes.labels": "Etiketter",
+  "notes.labelsHint": "Visa bokstavsetiketter på kartmarkörerna",
+  "notes.removeHint": "Ta bort den här markören",
+  "notes.toggle": "Noteringar",
+  "notes.toggleAria": "Visa eller dölj annoteringar",
+  "project.untitled": "Namnlöst projekt",
+  "pwa.dismissUpdate": "Stäng uppdateringsmeddelandet",
+  "pwa.updateAvailable": "En ny version av O-Analysis finns tillgänglig.",
+  "pwa.updateNow": "Uppdatera nu",
+  "rotation.degrees": "{degrees} grader",
+  "rotation.group": "Kartrotation",
+  "rotation.label": "Rotation",
+  "rotation.reset": "Återställ rotation",
+  "rotation.resetAria": "Återställ rotationen till 0 grader",
+  "rotation.rotate": "Rotera",
+  "save.failed": "Automatisk sparning misslyckades",
+  "save.saved": "Sparad {time}",
+  "save.saving": "Sparar…",
+  "status.coords": "X: {x} Y: {y}",
+  "status.credit": "av Anthony Riley ❤️",
+  "status.fitAria": "Zoom {zoom} %. Anpassa kartan till skärmen",
+  "status.fitHint": "Anpassa kartan till skärmen",
+  "status.legal": "Juridiskt",
+  "status.noCoords": "X: — Y: —",
+  "status.privacy": "Integritet",
+  "status.terms": "Villkor",
+  "status.textSize": "Textstorlek",
+  "status.textSizeShort": "Text",
+  "status.tool": "Verktyg: {tool}",
+  "status.zoomIn": "Zooma in",
+  "status.zoomOut": "Zooma ut",
+  "stroke.color": "Färg",
+  "stroke.colorAria": "Färg {color}",
+  "stroke.custom": "Egen färg",
+  "stroke.customHint": "Välj en egen färg",
+  "stroke.opacity": "Opacitet",
+  "stroke.opacityHint": "Genomskinlighet för ritade linjer och markörer",
+  "stroke.useColor": "Använd {color}",
+  "stroke.width": "Bredd",
+  "stroke.widthHint": "Linje- och markörbredd",
+  "style.commentTextSize": "Textstorlek för kommentarer",
+  "tool.eraser": "Sudd",
+  "tool.eraser.tip": "Klicka eller dra över linjer och markörer för att ta bort dem.",
+  "tool.eraser.touchTip": "Tryck eller dra över linjer och markörer för att ta bort dem.",
+  "tool.gpx": "Justera GPX",
+  "tool.gpx.tip": "Klicka på spåret för att lägga till punkter, dra för att flytta dem och högerklicka på en punkt för att ta bort den.",
+  "tool.gpx.touchTip": "Tryck på spåret för att lägga till punkter. Tryck länge på en punkt för att ta bort den.",
+  "tool.gpxNeedsFile": "Importera en GPX-fil först",
+  "tool.gpxShort": "GPX",
+  "tool.hotkeyLabel": "{tip} ({key})",
+  "tool.line": "Rita",
+  "tool.line.tip": "Klicka och dra för att rita linjer på kartan.",
+  "tool.line.touchTip": "Dra med fingret för att rita linjer på kartan.",
+  "tool.marker": "Markör",
+  "tool.marker.tip": "Klicka för att placera en numrerad markör med en kommentar.",
+  "tool.marker.touchTip": "Tryck för att placera en numrerad markör med en kommentar.",
+  "tool.pan": "Panorera",
+  "tool.pan.tip": "Dra kartan för att flytta runt. Håll ned mellanslag eller mittenknappen för tillfällig panorering.",
+  "tool.pan.touchTip": "Dra med ett finger, eller använd två fingrar för att panorera i alla verktyg.",
+  "tool.select": "Markera",
+  "tool.select.tip": "Klicka på linjer eller markörer för att markera dem. Tryck på Delete för att ta bort.",
+  "tool.select.touchTip": "Tryck på linjer eller markörer för att markera dem.",
+  "toolbar.annotations": "Annoteringar",
+  "toolbar.drawingTools": "Ritverktyg",
+  "toolbar.notes": "Noteringar",
+  "toolbar.strokeSettings": "Linjeinställningar",
+  "toolbar.style": "Stil",
+  "toolbar.viewAndStroke": "Vy och linjeinställningar",
+  "top.dismissError": "Stäng felmeddelandet",
+  "top.editGpxHint": "Ändra spårfärg, bredd eller justering",
+  "top.exportDisabled": "Importera en kartbild innan du exporterar",
+  "top.exportHint": "Förhandsgranska och ladda ner kartan med ritningar och annoteringar",
+  "top.history": "Historik",
+  "top.importGpxHint": "Importera en GPX-fil för att lägga en rutt över kartan",
+  "top.importImageHint": "Ladda upp en kartbild – PNG, JPG eller släpp en fil på duken",
+  "top.installApp": "Installera appen",
+  "top.installHint": "Installera O-Analysis som en skrivbordsapp",
+  "top.new": "Nytt",
+  "top.newHint": "Rensa duken och börja om",
+  "top.open": "Öppna",
+  "top.openHint": "Öppna ett sparat projekt ({ext})",
+  "top.projectName": "Projektnamn",
+  "top.projects": "Projekt",
+  "top.projectsHint": "Byt mellan sparade projekt",
+  "top.redo": "Gör om",
+  "top.redoHint": "Gör om (⌘⇧Z / Ctrl+Shift+Z)",
+  "top.replaceImageHint": "Ersätt den aktuella kartbilden",
+  "top.save": "Spara",
+  "top.saveDisabled": "Inget att spara ännu – importera en karta eller lägg till annoteringar först",
+  "top.saveHint": "Spara projektet som {ext}",
+  "top.undo": "Ångra",
+  "top.undoHint": "Ångra senaste åtgärden (⌘Z / Ctrl+Z)",
+  "top.updateApp": "Uppdatera appen",
+  "top.updateHint": "Ladda om för att använda den senaste versionen",
+  "touch.dismissTips": "Stäng tipsen",
+  "touch.tips": "Nyp för att zooma, använd två fingrar för att panorera. Tryck på ett verktyg och sedan på kartan för att rita eller placera markörer."
+}
diff --git a/src/main.tsx b/src/main.tsx
index 7eb46c5..d671406 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -5,16 +5,20 @@ import './index.css'
 import App from './App.tsx'
 import AppErrorBoundary from './components/AppErrorBoundary.tsx'
 import { initServiceWorker } from './pwa.ts'
+import { initI18n } from './i18n'
 
 // Avoid 0×0 shadow-cache canvases when browser zoom lowers devicePixelRatio.
 Konva.pixelRatio = 1
 
 initServiceWorker()
 
-createRoot(document.getElementById('root')!).render(
-  <StrictMode>
-    <AppErrorBoundary>
-      <App />
-    </AppErrorBoundary>
-  </StrictMode>,
-)
+// Load the saved or detected language before the first render, so nothing flashes in English
+void initI18n().then(() => {
+  createRoot(document.getElementById('root')!).render(
+    <StrictMode>
+      <AppErrorBoundary>
+        <App />
+      </AppErrorBoundary>
+    </StrictMode>,
+  )
+})
diff --git a/src/persistence/library.ts b/src/persistence/library.ts
index fb99791..c6d4697 100644
--- a/src/persistence/library.ts
+++ b/src/persistence/library.ts
@@ -7,6 +7,7 @@ import {
   del as delLegacy,
   get as getLegacy,
 } from 'idb-keyval'
+import { t } from '../i18n'
 import type {
   Annotation,
   DrawnPath,
@@ -15,8 +16,14 @@ import type {
   MarkerDisplayMode,
 } from '../types'
 
+/** Stored name for a project that has not been named. Shown translated via projectDisplayName(). */
 export const DEFAULT_PROJECT_NAME = 'Untitled project'
 
+/** The name to show on screen: the default name is translated, anything the user typed is shown as-is. */
+export function projectDisplayName(name: string): string {
+  return name === DEFAULT_PROJECT_NAME ? t('project.untitled') : name
+}
+
 /** Name for a project that has none: the map's name, or the default. */
 export function defaultProjectName(mapImageName: string | null | undefined): string {
   const base = mapImageName?.replace(/\.[^.]+$/, '').trim()
diff --git a/src/persistence/projectStorage.ts b/src/persistence/projectStorage.ts
index fbd2431..040ec27 100644
--- a/src/persistence/projectStorage.ts
+++ b/src/persistence/projectStorage.ts
@@ -1,5 +1,6 @@
 import type { PersistStorage, StorageValue } from 'zustand/middleware'
 import { hasUnsavedEdits, setSaveState } from '../saveStatus'
+import { t } from '../i18n'
 import type { MapImage } from '../types'
 import {
   dataUrlToBlob,
@@ -63,7 +64,7 @@ async function makeThumbnail(dataUrl: string): Promise<Blob | null> {
     const img = await new Promise<HTMLImageElement>((resolve, reject) => {
       const el = new Image()
       el.onload = () => resolve(el)
-      el.onerror = () => reject(new Error('Could not decode map image'))
+      el.onerror = () => reject(new Error(t('error.decodeMap')))
       el.src = dataUrl
     })
     const scale = Math.min(1, THUMBNAIL_MAX_PX / Math.max(img.width, img.height))
diff --git a/src/projectLibrary.ts b/src/projectLibrary.ts
index fe2d90c..e060cda 100644
--- a/src/projectLibrary.ts
+++ b/src/projectLibrary.ts
@@ -1,4 +1,5 @@
 import { useAppStore, type ProjectData } from './store'
+import { t } from './i18n'
 import {
   DEFAULT_PROJECT_NAME,
   defaultProjectName,
@@ -55,7 +56,7 @@ export async function openLibraryProject(id: string): Promise<void> {
   if (id === useAppStore.getState().projectId) return
   await flushProjectSaves()
   const state = await readProjectState(id)
-  if (!state) throw new Error('That project could not be found')
+  if (!state) throw new Error(t('error.projectNotFound'))
   adoptProjectState(state)
   await setActiveProjectId(id)
   useAppStore.getState().loadProject(state)
diff --git a/src/utils/export.ts b/src/utils/export.ts
index d28a885..caae0e7 100644
--- a/src/utils/export.ts
+++ b/src/utils/export.ts
@@ -1,8 +1,10 @@
 import { stageRef } from '../stageRef'
+import { t } from '../i18n'
 import { contentGroupRef } from '../contentGroupRef'
 import { useAppStore } from '../store'
 import { AnalyticsEvents, trackEvent } from '../analytics'
 import { exportScaleFor } from './exportScale'
+import { wrapText } from './textWrap'
 import { markerLabel } from './labels'
 import { drawMapMarkers } from './exportMarkers'
 import type { Annotation } from '../types'
@@ -18,7 +20,7 @@ let markersSuppressed = false
 /** Throws when the browser could not encode the canvas (e.g. it exceeded a canvas limit). */
 function assertEncodedPng(url: string): string {
   if (!url.startsWith('data:image/png') || url.length < 64) {
-    throw new Error('This map is too large to export on this device')
+    throw new Error(t('error.exportTooLarge'))
   }
   return url
 }
@@ -32,7 +34,7 @@ function loadImage(src: string): Promise<HTMLImageElement> {
   return new Promise((resolve, reject) => {
     const img = new window.Image()
     img.onload = () => resolve(img)
-    img.onerror = () => reject(new Error('Failed to render export image'))
+    img.onerror = () => reject(new Error(t('error.renderExport')))
     img.src = src
   })
 }
@@ -91,32 +93,6 @@ export async function renderExportPreviews(
 }
 
 /** Splits text into lines that fit maxWidth, honouring explicit newlines. */
-function wrapText(
-  ctx: CanvasRenderingContext2D,
-  text: string,
-  maxWidth: number,
-): string[] {
-  const lines: string[] = []
-  for (const paragraph of text.split('\n')) {
-    const words = paragraph.split(/\s+/).filter(Boolean)
-    if (words.length === 0) {
-      lines.push('')
-      continue
-    }
-    let line = words[0]
-    for (const word of words.slice(1)) {
-      if (ctx.measureText(`${line} ${word}`).width <= maxWidth) {
-        line = `${line} ${word}`
-      } else {
-        lines.push(line)
-        line = word
-      }
-    }
-    lines.push(line)
-  }
-  return lines
-}
-
 interface SidebarEntry {
   annotation: Annotation
   index: number
@@ -211,7 +187,7 @@ function drawSidebar(
     if (c === 0) {
       ctx.fillStyle = '#18181b'
       ctx.font = `600 ${fontSize * 1.1}px ${font}`
-      ctx.fillText('Annotations', colX + pad, pad + fontSize)
+      ctx.fillText(t('notes.heading'), colX + pad, pad + fontSize)
     }
 
     if (c > 0) {
diff --git a/src/utils/files.ts b/src/utils/files.ts
index 9163c5a..35511cf 100644
--- a/src/utils/files.ts
+++ b/src/utils/files.ts
@@ -2,6 +2,7 @@ import { useAppStore } from '../store'
 import { AnalyticsEvents, trackEvent } from '../analytics'
 import { buildTrack, parseGpx } from './gpx'
 import { isProjectFile, openProjectFile } from './project'
+import { t } from '../i18n'
 
 export const MAX_IMAGE_BYTES = 20 * 1024 * 1024
 
@@ -15,7 +16,7 @@ function loadImageElement(src: string): Promise<HTMLImageElement> {
   return new Promise((resolve, reject) => {
     const img = new window.Image()
     img.onload = () => resolve(img)
-    img.onerror = () => reject(new Error('Could not decode the image file'))
+    img.onerror = () => reject(new Error(t('error.decodeImage')))
     img.src = src
   })
 }
@@ -24,7 +25,7 @@ function readFileAsDataUrl(file: File): Promise<string> {
   return new Promise((resolve, reject) => {
     const reader = new FileReader()
     reader.onload = () => resolve(reader.result as string)
-    reader.onerror = () => reject(new Error('Could not read the image file'))
+    reader.onerror = () => reject(new Error(t('error.readImage')))
     reader.readAsDataURL(file)
   })
 }
@@ -38,12 +39,12 @@ export async function importImageFile(
   setImportError(null)
 
   if (!file.type.startsWith('image/')) {
-    setImportError(`"${file.name}" is not an image file`)
+    setImportError(t('error.notImage', { name: file.name }))
     return
   }
   if (file.size > MAX_IMAGE_BYTES) {
     setImportError(
-      `Image is too large (${formatMb(file.size)}). Maximum size is 20MB.`,
+      t('error.imageTooLarge', { size: formatMb(file.size) }),
     )
     return
   }
@@ -63,7 +64,7 @@ export async function importImageFile(
       source,
     })
   } catch (error) {
-    setImportError(error instanceof Error ? error.message : 'Image import failed')
+    setImportError(error instanceof Error ? error.message : t('error.imageImport'))
   }
 }
 
@@ -90,7 +91,7 @@ export async function importGpxFile(
     })
   } catch (error) {
     store.setImportError(
-      error instanceof Error ? error.message : 'GPX import failed',
+      error instanceof Error ? error.message : t('error.gpxImport'),
     )
   }
 }
@@ -107,7 +108,7 @@ export async function importDroppedFiles(files: FileList): Promise<void> {
     } else {
       useAppStore
         .getState()
-        .setImportError(`Unsupported file type: "${file.name}"`)
+        .setImportError(t('error.unsupportedFile', { name: file.name }))
     }
   }
 }
diff --git a/src/utils/gpx.ts b/src/utils/gpx.ts
index f25b301..e5404fa 100644
--- a/src/utils/gpx.ts
+++ b/src/utils/gpx.ts
@@ -4,6 +4,7 @@ import {
   defaultPaceScale,
   hasTrackTiming,
 } from './gpxMetrics'
+import { t } from '../i18n'
 
 interface ParsedGpx {
   name: string
@@ -59,7 +60,7 @@ function parseHeartRateBpm(node: Element): number | undefined {
 export function parseGpx(xml: string, fileName: string): ParsedGpx {
   const doc = new DOMParser().parseFromString(xml, 'application/xml')
   if (doc.querySelector('parsererror')) {
-    throw new Error('Not a valid GPX file')
+    throw new Error(t('error.notGpx'))
   }
 
   let pointNodes = Array.from(doc.querySelectorAll('trkpt'))
@@ -83,7 +84,7 @@ export function parseGpx(xml: string, fileName: string): ParsedGpx {
   }
 
   if (projected.length < 2) {
-    throw new Error('GPX file contains no usable track points')
+    throw new Error(t('error.noGpxPoints'))
   }
 
   let minX = Infinity
diff --git a/src/utils/markerComments.ts b/src/utils/markerComments.ts
index 80f12a4..6d335ee 100644
--- a/src/utils/markerComments.ts
+++ b/src/utils/markerComments.ts
@@ -1,3 +1,5 @@
+import { wrapText } from './textWrap'
+
 export const COMMENT_FONT_SIZE = 8
 export const COMMENT_MAX_TEXT_WIDTH = 68
 export const COMMENT_PADDING = 3
@@ -79,32 +81,6 @@ export function rightEdgeFromTextWidth(
   return ((clampCommentBoxWidth(textWidth) + COMMENT_PADDING * 2) / 2) * scale
 }
 
-function wrapText(
-  ctx: CanvasRenderingContext2D,
-  text: string,
-  maxWidth: number,
-): string[] {
-  const lines: string[] = []
-  for (const paragraph of text.split('\n')) {
-    const words = paragraph.split(/\s+/).filter(Boolean)
-    if (words.length === 0) {
-      lines.push('')
-      continue
-    }
-    let line = words[0]
-    for (const word of words.slice(1)) {
-      if (ctx.measureText(`${line} ${word}`).width <= maxWidth) {
-        line = `${line} ${word}`
-      } else {
-        lines.push(line)
-        line = word
-      }
-    }
-    lines.push(line)
-  }
-  return lines
-}
-
 export interface CommentBoxMetrics {
   width: number
   height: number
diff --git a/src/utils/project.ts b/src/utils/project.ts
index a78c254..f9ba27a 100644
--- a/src/utils/project.ts
+++ b/src/utils/project.ts
@@ -1,6 +1,7 @@
 import { useAppStore, type ProjectData } from '../store'
 import { AnalyticsEvents, trackEvent } from '../analytics'
 import { importProject } from '../projectLibrary'
+import { t } from '../i18n'
 import { PROJECT_FORMAT, PROJECT_VERSION, validateProjectFile, type ProjectFile } from './projectValidation'
 
 export const PROJECT_FILE_EXTENSION = '.anal'
@@ -31,7 +32,7 @@ export function saveProjectFile(): void {
     rotation: useAppStore.getState().viewport.rotation,
   }
   if (!hasProjectContent(project)) {
-    setImportError('Nothing to save — import a map or add content first')
+    setImportError(t('error.nothingToSave'))
     return
   }
 
@@ -68,14 +69,14 @@ export async function openSampleProject(): Promise<void> {
   try {
     const response = await fetch('/sample.anal')
     if (!response.ok) {
-      throw new Error('Sample project not found')
+      throw new Error(t('error.sampleNotFound'))
     }
     const parsed = validateProjectFile(JSON.parse(await response.text()))
     await importProject(parsed, parsed.name)
     trackEvent(AnalyticsEvents.OPEN_SAMPLE_PROJECT)
   } catch (error) {
     setImportError(
-      error instanceof Error ? error.message : 'Failed to load sample project',
+      error instanceof Error ? error.message : t('error.loadSample'),
     )
   }
 }
@@ -89,7 +90,7 @@ export async function openProjectFile(
   setImportError(null)
 
   if (!isProjectFile(file)) {
-    setImportError(`Not a project file — expected ${PROJECT_FILE_EXTENSION}`)
+    setImportError(t('error.notProjectFile', { ext: PROJECT_FILE_EXTENSION }))
     return
   }
 
@@ -105,7 +106,7 @@ export async function openProjectFile(
     })
   } catch (error) {
     setImportError(
-      error instanceof Error ? error.message : 'Failed to open project file',
+      error instanceof Error ? error.message : t('error.openProject'),
     )
   }
 }
diff --git a/src/utils/projectValidation.ts b/src/utils/projectValidation.ts
index 9063131..06ac29e 100644
--- a/src/utils/projectValidation.ts
+++ b/src/utils/projectValidation.ts
@@ -1,4 +1,5 @@
 import type { ProjectData } from '../store'
+import { t } from '../i18n'
 
 export const PROJECT_FORMAT = 'map-analysis'
 export const PROJECT_VERSION = 1
@@ -32,12 +33,12 @@ function assertItems(
   isValid: (item: unknown) => boolean,
 ): void {
   if (!Array.isArray(items)) {
-    throw new Error(`Invalid ${label} in project file`)
+    throw new Error(t('error.invalidEntry', { label }))
   }
   const badIndex = items.findIndex((item) => !isValid(item))
   if (badIndex !== -1) {
     throw new Error(
-      `Invalid ${label} in project file (entry ${badIndex + 1} is damaged)`,
+      t('error.damagedEntry', { label, index: badIndex + 1 }),
     )
   }
 }
@@ -93,27 +94,27 @@ function isValidAnnotation(v: unknown): boolean {
 
 export function validateProjectFile(raw: unknown): ProjectFile {
   if (!isRecord(raw)) {
-    throw new Error('Project file is not valid JSON')
+    throw new Error(t('error.notJson'))
   }
 
   if (raw.format !== PROJECT_FORMAT) {
-    throw new Error('Not an O-Analysis project file')
+    throw new Error(t('error.notOurs'))
   }
   if (raw.version !== PROJECT_VERSION) {
-    throw new Error(`Unsupported project version: ${String(raw.version)}`)
+    throw new Error(t('error.version', { version: String(raw.version) }))
   }
   if (raw.mapImage !== null && !isValidMapImage(raw.mapImage)) {
-    throw new Error('Invalid map image in project file')
+    throw new Error(t('error.invalidMap'))
   }
   if (raw.name !== undefined && typeof raw.name !== 'string') {
-    throw new Error('Invalid project name in project file')
+    throw new Error(t('error.invalidName'))
   }
   if (raw.rotation !== undefined && !isFiniteNumber(raw.rotation)) {
-    throw new Error('Invalid rotation in project file')
+    throw new Error(t('error.invalidRotation'))
   }
-  assertItems('GPX tracks', raw.tracks, isValidTrack)
-  assertItems('drawings', raw.paths, isValidPath)
-  assertItems('annotations', raw.annotations, isValidAnnotation)
+  assertItems(t('error.labelTracks'), raw.tracks, isValidTrack)
+  assertItems(t('error.labelDrawings'), raw.paths, isValidPath)
+  assertItems(t('error.labelAnnotations'), raw.annotations, isValidAnnotation)
 
   return raw as unknown as ProjectFile
 }
diff --git a/src/utils/textWrap.test.ts b/src/utils/textWrap.test.ts
new file mode 100644
index 0000000..fe9e3bc
--- /dev/null
+++ b/src/utils/textWrap.test.ts
@@ -0,0 +1,34 @@
+import { describe, expect, it } from 'vitest'
+import { wrapText } from './textWrap'
+
+/** Stub measuring context: every character is 10px wide. */
+const ctx = {
+  measureText: (text: string) => ({ width: text.length * 10 }),
+} as unknown as CanvasRenderingContext2D
+
+describe('wrapText', () => {
+  it('wraps on spaces to the maximum width', () => {
+    expect(wrapText(ctx, 'one two three', 80)).toEqual(['one two', 'three'])
+  })
+
+  it('keeps explicit newlines and blank lines', () => {
+    expect(wrapText(ctx, 'a\n\nb', 200)).toEqual(['a', '', 'b'])
+  })
+
+  it('breaks a single word that is wider than the column (long Finnish compounds)', () => {
+    const lines = wrapText(ctx, 'Lentokonehangaarikonsultointi', 100)
+    expect(lines.length).toBeGreaterThan(1)
+    expect(lines.join('')).toBe('Lentokonehangaarikonsultointi')
+    for (const line of lines) {
+      expect(line.length * 10).toBeLessThanOrEqual(100)
+    }
+  })
+
+  it('does not insert spaces into a broken word', () => {
+    expect(wrapText(ctx, 'abcdefghij', 30)).toEqual(['abc', 'def', 'ghi', 'j'])
+  })
+
+  it('keeps a short word on the line where it fits after a broken word', () => {
+    expect(wrapText(ctx, 'abcdefgh ok', 80)).toEqual(['abcdefgh', 'ok'])
+  })
+})
diff --git a/src/utils/textWrap.ts b/src/utils/textWrap.ts
new file mode 100644
index 0000000..e39bcf8
--- /dev/null
+++ b/src/utils/textWrap.ts
@@ -0,0 +1,58 @@
+/**
+ * Canvas text wrapping for the exported annotation sidebar and map comments.
+ * Works with any 2D context, so tests can pass a stub that measures text.
+ */
+/** Splits one word that is wider than maxWidth (e.g. long Finnish compounds) into pieces that fit. */
+function breakWord(
+  ctx: CanvasRenderingContext2D,
+  word: string,
+  maxWidth: number,
+): string[] {
+  const pieces: string[] = []
+  let piece = ''
+  for (const char of word) {
+    if (piece && ctx.measureText(piece + char).width > maxWidth) {
+      pieces.push(piece)
+      piece = char
+    } else {
+      piece += char
+    }
+  }
+  if (piece) pieces.push(piece)
+  return pieces
+}
+
+/** Wraps text to maxWidth, honouring explicit newlines and breaking words that cannot fit. */
+export function wrapText(
+  ctx: CanvasRenderingContext2D,
+  text: string,
+  maxWidth: number,
+): string[] {
+  const lines: string[] = []
+  for (const paragraph of text.split('\n')) {
+    const words = paragraph.split(/\s+/).filter(Boolean)
+    if (words.length === 0) {
+      lines.push('')
+      continue
+    }
+    let line = ''
+    for (const word of words) {
+      const candidate = line ? `${line} ${word}` : word
+      if (ctx.measureText(candidate).width <= maxWidth) {
+        line = candidate
+        continue
+      }
+      if (line) lines.push(line)
+      line = ''
+      if (ctx.measureText(word).width <= maxWidth) {
+        line = word
+        continue
+      }
+      const pieces = breakWord(ctx, word, maxWidth)
+      lines.push(...pieces.slice(0, -1))
+      line = pieces[pieces.length - 1] ?? ''
+    }
+    lines.push(line)
+  }
+  return lines
+}
diff --git a/tsconfig.app.json b/tsconfig.app.json
index 6830b6f..345ba12 100644
--- a/tsconfig.app.json
+++ b/tsconfig.app.json
@@ -6,6 +6,7 @@
     "module": "esnext",
     "types": ["vite/client"],
     "allowArbitraryExtensions": true,
+    "resolveJsonModule": true,
     "skipLibCheck": true,
 
     /* Bundler mode */
diff --git a/vite.config.ts b/vite.config.ts
index e185455..309ae34 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -2,6 +2,9 @@ import { defineConfig, loadEnv } from 'vite'
 import react from '@vitejs/plugin-react'
 import { VitePWA } from 'vite-plugin-pwa'
 
+/** Vite names each language chunk after its locale code, e.g. sv-*.js or pt-BR-*.js */
+const LOCALE_CHUNK_PREFIX = '{sv,nb,fi,da,es,fr,pt-BR,pt-PT}-'
+
 // https://vite.dev/config/
 export default defineConfig(({ command, mode }) => {
   const env = loadEnv(mode, process.cwd(), '')
@@ -61,6 +64,15 @@ export default defineConfig(({ command, mode }) => {
       },
       workbox: {
         globPatterns: ['**/*.{js,css,html,ico,png,svg,woff2}'],
+        // Language packs download on first use rather than on install (see runtimeCaching)
+        globIgnores: [`**/${LOCALE_CHUNK_PREFIX}*.js`],
+        runtimeCaching: [
+          {
+            urlPattern: new RegExp(`/assets/${LOCALE_CHUNK_PREFIX}[^/]*\\.js$`),
+            handler: 'CacheFirst',
+            options: { cacheName: 'language-packs' },
+          },
+        ],
       },
     }),
   ],