diff --git a/packages/react-native/Libraries/LogBox/Data/LogBoxData.js b/packages/react-native/Libraries/LogBox/Data/LogBoxData.js
index 37fb35b9f5d3..3ba76ae2cdfe 100644
--- a/packages/react-native/Libraries/LogBox/Data/LogBoxData.js
+++ b/packages/react-native/Libraries/LogBox/Data/LogBoxData.js
@@ -20,7 +20,6 @@ import type {
 
 import DebuggerSessionObserver from '../../../src/private/devsupport/rndevtools/FuseboxSessionObserver';
 import parseErrorStack from '../../Core/Devtools/parseErrorStack';
-import NativeDevSettings from '../../NativeModules/specs/NativeDevSettings';
 import NativeLogBox from '../../NativeModules/specs/NativeLogBox';
 import LogBoxLog from './LogBoxLog';
 import {parseLogBoxException} from './parseLogBoxLog';
@@ -493,6 +492,10 @@ function showFuseboxWarningsMigrationMessageOnce() {
     return;
   }
   hasShownFuseboxWarningsMigrationMessage = true;
+
+  const NativeDevSettings =
+    require('../../NativeModules/specs/NativeDevSettings').default;
+
   appendNewLog(
     new LogBoxLog({
       level: 'warn',
diff --git a/packages/react-native/src/private/webapis/performance/__tests__/Performance-benchmark-itest.js b/packages/react-native/src/private/webapis/performance/__tests__/Performance-benchmark-itest.js
index 2076f696cf06..b35b952b40e8 100644
--- a/packages/react-native/src/private/webapis/performance/__tests__/Performance-benchmark-itest.js
+++ b/packages/react-native/src/private/webapis/performance/__tests__/Performance-benchmark-itest.js
@@ -135,4 +135,7 @@ Fantom.unstable_benchmark
       },
       afterEach: clearMarksAndMeasures,
     },
-  );
+  )
+  .test('console.timeStamp', () => {
+    console.timeStamp('label');
+  });
diff --git a/private/react-native-fantom/runner/formatFantomConfig.js b/private/react-native-fantom/runner/formatFantomConfig.js
index 642a8f647db3..702a49db475f 100644
--- a/private/react-native-fantom/runner/formatFantomConfig.js
+++ b/private/react-native-fantom/runner/formatFantomConfig.js
@@ -14,6 +14,7 @@ import type {HermesVariant} from '../runner/utils';
 
 import {
   FantomTestConfigHermesVariant,
+  FantomTestConfigJsMode,
   FantomTestConfigMode,
 } from '../runner/getFantomTestConfigs';
 import {getOverrides} from './getFantomTestConfigs';
@@ -29,6 +30,15 @@ function formatFantomMode(mode: FantomTestConfigMode): string {
   }
 }
 
+function formatFantomJsMode(mode: FantomTestConfigJsMode): string {
+  switch (mode) {
+    case FantomTestConfigJsMode.Development:
+      return 'jsMode 🐛';
+    case FantomTestConfigJsMode.Optimized:
+      return 'jsMode 🚀';
+  }
+}
+
 function formatFantomHermesVariant(hermesVariant: HermesVariant): string {
   switch (hermesVariant) {
     case FantomTestConfigHermesVariant.Hermes:
@@ -61,6 +71,16 @@ export default function formatFantomConfig(config: FantomTestConfig): string {
     parts.push(formatFantomMode(overrides.mode));
   }
 
+  // Show if the jsMode is different from the mode
+  if (
+    (config.jsMode === FantomTestConfigJsMode.Optimized &&
+      config.mode !== FantomTestConfigMode.Optimized) ||
+    (config.jsMode === FantomTestConfigJsMode.Development &&
+      config.mode === FantomTestConfigMode.Optimized)
+  ) {
+    parts.push(formatFantomJsMode(config.jsMode));
+  }
+
   if (overrides.hermesVariant) {
     parts.push(formatFantomHermesVariant(overrides.hermesVariant));
   }
diff --git a/private/react-native-fantom/runner/getFantomTestConfigs.js b/private/react-native-fantom/runner/getFantomTestConfigs.js
index 2b9ba1e3028e..1db14343ed96 100644
--- a/private/react-native-fantom/runner/getFantomTestConfigs.js
+++ b/private/react-native-fantom/runner/getFantomTestConfigs.js
@@ -26,6 +26,11 @@ export enum FantomTestConfigMode {
   Optimized,
 }
 
+export enum FantomTestConfigJsMode {
+  Development,
+  Optimized,
+}
+
 export type FantomTestConfigCommonFeatureFlags = Partial<{
   [key in keyof CommonFeatureFlags]: CommonFeatureFlags[key]['defaultValue'],
 }>;
@@ -46,12 +51,14 @@ export type FantomTestConfigFeatureFlags = {
 
 export type FantomTestConfig = {
   mode: FantomTestConfigMode,
+  jsMode: FantomTestConfigJsMode,
   hermesVariant: HermesVariant,
   flags: FantomTestConfigFeatureFlags,
 };
 
 export type PartialFantomTestConfig = {
   mode?: FantomTestConfigMode,
+  jsMode?: FantomTestConfigJsMode,
   hermesVariant?: HermesVariant,
   flags?: Partial<FantomTestConfigFeatureFlags>,
 };
@@ -61,6 +68,9 @@ export const FantomTestConfigHermesVariant = HermesVariant;
 export const DEFAULT_MODE: FantomTestConfigMode =
   FantomTestConfigMode.DevelopmentWithSource;
 
+export const DEFAULT_JS_MODE: FantomTestConfigJsMode =
+  FantomTestConfigJsMode.Development;
+
 export const DEFAULT_HERMES_VARIANT: HermesVariant = HermesVariant.Hermes;
 
 export const DEFAULT_FEATURE_FLAGS: FantomTestConfigFeatureFlags = {
@@ -84,6 +94,7 @@ const MAX_FANTOM_CONFIGURATION_VARIATIONS = 12;
 
 const VALID_FANTOM_PRAGMAS = [
   'fantom_mode',
+  'fantom_js_mode',
   'fantom_flags',
   'fantom_hermes_variant',
   'fantom_react_fb_flags',
@@ -131,6 +142,7 @@ export function getOverrides(
  * /**
  *  * @flow strict-local
  *  * @fantom_mode opt
+ *  * @fantom_js_mode dev
  *  * @fantom_hermes_variant static_hermes_stable
  *  * @fantom_flags commonTestFlag:true
  *  * @fantom_flags jsOnlyTestFlag:true
@@ -163,6 +175,7 @@ export default function getFantomTestConfigs(
 
   const config: FantomTestConfig = {
     mode: DEFAULT_MODE,
+    jsMode: DEFAULT_JS_MODE,
     hermesVariant: DEFAULT_HERMES_VARIANT,
     flags: {
       common: {
@@ -217,6 +230,39 @@ export default function getFantomTestConfigs(
     }
   }
 
+  const maybeJsMode = pragmas.fantom_js_mode;
+
+  if (maybeJsMode != null) {
+    if (Array.isArray(maybeJsMode)) {
+      throw new Error('Expected a single value for @fantom_js_mode');
+    }
+
+    const jsMode = maybeJsMode;
+
+    switch (jsMode) {
+      case 'dev':
+        config.jsMode = FantomTestConfigJsMode.Development;
+        break;
+      case 'opt':
+        config.jsMode = FantomTestConfigJsMode.Optimized;
+        break;
+      case '*':
+        configVariations.push([
+          {jsMode: FantomTestConfigJsMode.Development},
+          {jsMode: FantomTestConfigJsMode.Optimized},
+        ]);
+        break;
+      default:
+        throw new Error(`Invalid Fantom jsMode: ${jsMode}`);
+    }
+  } else {
+    // If not set, match the native mode
+    config.jsMode =
+      config.mode === FantomTestConfigMode.Optimized
+        ? FantomTestConfigJsMode.Optimized
+        : FantomTestConfigJsMode.Development;
+  }
+
   const maybeHermesVariant = pragmas.fantom_hermes_variant;
 
   if (maybeHermesVariant != null) {
@@ -378,6 +424,7 @@ function getConfigurationVariations(
   for (const currentConfigVariation of currentConfigVariations) {
     const currentConfigWithVariation = {
       mode: currentConfigVariation.mode ?? config.mode,
+      jsMode: currentConfigVariation.jsMode ?? config.jsMode,
       hermesVariant:
         currentConfigVariation.hermesVariant ?? config.hermesVariant,
       flags: {
diff --git a/private/react-native-fantom/runner/runner.js b/private/react-native-fantom/runner/runner.js
index 453beb282023..edb4f202b295 100644
--- a/private/react-native-fantom/runner/runner.js
+++ b/private/react-native-fantom/runner/runner.js
@@ -24,7 +24,10 @@ import entrypointTemplate from './entrypoint-template';
 import * as EnvironmentOptions from './EnvironmentOptions';
 import formatFantomConfig from './formatFantomConfig';
 import getFantomTestConfigs from './getFantomTestConfigs';
-import {FantomTestConfigMode} from './getFantomTestConfigs';
+import {
+  FantomTestConfigJsMode,
+  FantomTestConfigMode,
+} from './getFantomTestConfigs';
 import {
   getInitialSnapshotData,
   updateSnapshotsAndGetJestSnapshotResult,
@@ -317,12 +320,14 @@ module.exports = async function runTest(
       path.basename(testJSBundlePath, '.js') + '.map',
     );
 
+    const devMode = testConfig.jsMode !== FantomTestConfigJsMode.Optimized;
+
     await Metro.runBuild(metroConfig, {
       entry: entrypointPath,
       out: testJSBundlePath,
       platform: 'android',
-      minify: testConfig.mode === FantomTestConfigMode.Optimized,
-      dev: testConfig.mode !== FantomTestConfigMode.Optimized,
+      minify: !devMode,
+      dev: devMode,
       sourceMap: true,
       sourceMapUrl: sourceMapPath,
     });