camilopires · Oct 18, 2026
diff --git a/packages/react-native/Libraries/Components/AccessibilityInfo/AccessibilityInfo.js b/packages/react-native/Libraries/Components/AccessibilityInfo/AccessibilityInfo.js
@@ -27,14 +27,14 @@ type AccessibilityEventDefinitionsAndroid = {
 // Events that are only supported on iOS.
 type AccessibilityEventDefinitionsIOS = {
   announcementFinished: [{announcement: string, success: boolean}],
-  boldTextChanged: [boolean],
   darkerSystemColorsChanged: [boolean],
   reduceTransparencyChanged: [boolean],
 };
 
 type AccessibilityEventDefinitions = {
   ...AccessibilityEventDefinitionsAndroid,
   ...AccessibilityEventDefinitionsIOS,
+  boldTextChanged: [boolean],
   change: [boolean], // screenReaderChanged
   grayscaleChanged: [boolean],
   invertColorsChanged: [boolean],
@@ -52,6 +52,7 @@ const EventNames: Map<keyof AccessibilityEventDefinitions, string> =
         ['change', 'touchExplorationDidChange'],
         ['reduceMotionChanged', 'reduceMotionDidChange'],
         ['highTextContrastChanged', 'highTextContrastDidChange'],
+        ['boldTextChanged', 'boldTextDidChange'],
         ['screenReaderChanged', 'touchExplorationDidChange'],
         ['accessibilityServiceChanged', 'accessibilityServiceDidChange'],
         ['invertColorsChanged', 'invertColorDidChange'],
@@ -81,11 +82,19 @@ const AccessibilityInfo = {
    * Returns a promise which resolves to a boolean.
    * The result is `true` when bold text is enabled and `false` otherwise.
    *
-   * @platform ios
+   * On Android, bold text is supported on Android 12 (API 31) and later;
+   * earlier versions always resolve to `false`.
    */
   isBoldTextEnabled(): Promise<boolean> {
     if (Platform.OS === 'android') {
-      return Promise.resolve(false);
+      return new Promise(resolve => {
+        if (NativeAccessibilityInfoAndroid?.isBoldTextEnabled != null) {
+          NativeAccessibilityInfoAndroid.isBoldTextEnabled(resolve);
+        } else {
+          // Native code that predates Android support keeps the old behavior.
+          resolve(false);
+        }
+      });
     } else {
       return new Promise((resolve, reject) => {
         if (NativeAccessibilityManagerIOS != null) {
@@ -388,12 +397,12 @@ const AccessibilityInfo = {
    * - `invertColorsChanged`: Fires when the state of the invert colors toggle
    *   changes. The argument to the event handler is a boolean. The boolean is `true` when invert
    *   colors is enabled and `false` otherwise.
+   * - `boldTextChanged`: Fires when the state of the bold text toggle changes.
+   *   The argument to the event handler is a boolean. The boolean is `true` when a bold text
+   *   is enabled and `false` otherwise. On Android, requires Android 12 (API 31) or later.
    *
    * These events are only supported on iOS:
    *
-   * - `boldTextChanged`: iOS-only event. Fires when the state of the bold text toggle changes.
-   *   The argument to the event handler is a boolean. The boolean is `true` when a bold text
-   *   is enabled and `false` otherwise.
    * - `reduceTransparencyChanged`: iOS-only event. Fires when the state of the reduce transparency
    *   toggle changes.  The argument to the event handler is a boolean. The boolean is `true`
    *   when a reduce transparency is enabled and `false` otherwise.

diff --git a/...-native/Libraries/Components/AccessibilityInfo/__tests__/AccessibilityInfo-events-test.js b/...-native/Libraries/Components/AccessibilityInfo/__tests__/AccessibilityInfo-events-test.js
@@ -0,0 +1,78 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import typeof RCTDeviceEventEmitterType from '../../../EventEmitter/RCTDeviceEventEmitter';
+import typeof AccessibilityInfoType from '../AccessibilityInfo';
+
+const invariant = require('invariant');
+
+jest.unmock('../AccessibilityInfo');
+
+type LoadedModules = {
+  AccessibilityInfo: AccessibilityInfoType,
+  RCTDeviceEventEmitter: RCTDeviceEventEmitterType,
+};
+
+// `AccessibilityInfo` picks its native event names when it is first loaded,
+// so each platform needs a fresh module registry.
+function loadForPlatform(os: 'android' | 'ios'): LoadedModules {
+  let modules: ?LoadedModules = null;
+  jest.isolateModules(() => {
+    const Platform = require('../../../Utilities/Platform').default;
+    /* $FlowFixMe[incompatible-type] */
+    Platform.OS = os;
+    modules = {
+      AccessibilityInfo: require('../AccessibilityInfo').default,
+      RCTDeviceEventEmitter:
+        require('../../../EventEmitter/RCTDeviceEventEmitter').default,
+    };
+  });
+  invariant(modules != null, 'Expected modules to load');
+  return modules;
+}
+
+describe('AccessibilityInfo events', () => {
+  describe('Android', () => {
+    it('delivers boldTextDidChange as boldTextChanged', () => {
+      const {AccessibilityInfo, RCTDeviceEventEmitter} =
+        loadForPlatform('android');
+      const handler = jest.fn();
+
+      const subscription = AccessibilityInfo.addEventListener(
+        'boldTextChanged',
+        handler,
+      );
+      RCTDeviceEventEmitter.emit('boldTextDidChange', true);
+      subscription.remove();
+      RCTDeviceEventEmitter.emit('boldTextDidChange', false);
+
+      expect(handler).toHaveBeenCalledTimes(1);
+      expect(handler).toHaveBeenCalledWith(true);
+    });
+  });
+
+  describe('iOS', () => {
+    it('delivers boldTextChanged as boldTextChanged', () => {
+      const {AccessibilityInfo, RCTDeviceEventEmitter} = loadForPlatform('ios');
+      const handler = jest.fn();
+
+      const subscription = AccessibilityInfo.addEventListener(
+        'boldTextChanged',
+        handler,
+      );
+      RCTDeviceEventEmitter.emit('boldTextChanged', true);
+      subscription.remove();
+      RCTDeviceEventEmitter.emit('boldTextChanged', false);
+
+      expect(handler).toHaveBeenCalledTimes(1);
+      expect(handler).toHaveBeenCalledWith(true);
+    });
+  });
+});
diff --git a/...s/react-native/Libraries/Components/AccessibilityInfo/__tests__/AccessibilityInfo-test.js b/...s/react-native/Libraries/Components/AccessibilityInfo/__tests__/AccessibilityInfo-test.js
@@ -104,6 +104,7 @@ let mockNativeAccessibilityManagerIOS: {
 };
 
 const ANDROID_RECOMMENDED_TIMEOUT = 6000;
+const mockIsBoldTextEnabledAndroid = jest.fn(onSuccess => onSuccess(true));
 const mockIsHighTextContrastEnabled = jest.fn(onSuccess => onSuccess(true));
 const mockIsGrayscaleEnabled = jest.fn(onSuccess => onSuccess(true));
 const mockIsInvertColorsEnabled = jest.fn(onSuccess => onSuccess(true));
@@ -114,6 +115,10 @@ const mockGetRecommendedTimeoutMillis = jest.fn((originalTimeout, onSuccess) =>
   onSuccess(ANDROID_RECOMMENDED_TIMEOUT),
 );
 let mockNativeAccessibilityInfoAndroid: {
+  isBoldTextEnabled: JestMockFn<
+    [onSuccess: (isBoldTextEnabled: boolean) => void],
+    void,
+  > | null,
   isHighTextContrastEnabled: JestMockFn<
     [onSuccess: (isHighTextContrastEnabled: boolean) => void],
     void,
@@ -143,6 +148,7 @@ let mockNativeAccessibilityInfoAndroid: {
     void,
   > | null,
 } = {
+  isBoldTextEnabled: mockIsBoldTextEnabledAndroid,
   isHighTextContrastEnabled: mockIsHighTextContrastEnabled,
   isGrayscaleEnabled: mockIsGrayscaleEnabled,
   isInvertColorsEnabled: mockIsInvertColorsEnabled,
@@ -176,10 +182,22 @@ describe('AccessibilityInfo', () => {
 
   describe('isBoldTextEnabled', () => {
     describe('Android', () => {
-      it('should return immediately', async () => {
+      it('should call isBoldTextEnabled if available', async () => {
+        /* $FlowFixMe[incompatible-type] */
+        Platform.OS = 'android';
+
+        const isBoldTextEnabled = await AccessibilityInfo.isBoldTextEnabled();
+
+        expect(mockIsBoldTextEnabledAndroid).toHaveBeenCalled();
+        expect(isBoldTextEnabled).toBe(true);
+      });
+
+      it('should return false if isBoldTextEnabled is not available', async () => {
         /* $FlowFixMe[incompatible-type] */
         Platform.OS = 'android';
 
+        mockNativeAccessibilityInfoAndroid.isBoldTextEnabled = null;
+
         const isBoldTextEnabled = await AccessibilityInfo.isBoldTextEnabled();
 
         expect(isBoldTextEnabled).toBe(false);
@@ -805,6 +823,7 @@ describe('AccessibilityInfo', () => {
       mockNativeAccessibilityManagerIOS;
 
     mockNativeAccessibilityInfoAndroid = {
+      isBoldTextEnabled: mockIsBoldTextEnabledAndroid,
       isHighTextContrastEnabled: mockIsHighTextContrastEnabled,
       isGrayscaleEnabled: mockIsGrayscaleEnabled,
       isInvertColorsEnabled: mockIsInvertColorsEnabled,

diff --git a/...oid/src/main/java/com/facebook/react/modules/accessibilityinfo/AccessibilityInfoModule.kt b/...oid/src/main/java/com/facebook/react/modules/accessibilityinfo/AccessibilityInfoModule.kt
@@ -7,8 +7,10 @@
 
 package com.facebook.react.modules.accessibilityinfo
 
+import android.content.ComponentCallbacks
 import android.content.ContentResolver
 import android.content.Context
+import android.content.res.Configuration
 import android.database.ContentObserver
 import android.net.Uri
 import android.os.Build
@@ -72,6 +74,22 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
           }
         }
       }
+  // Listener that is notified when the bold text setting (font weight adjustment) changes.
+  private val boldTextCallbacks: ComponentCallbacks =
+      object : ComponentCallbacks {
+        override fun onConfigurationChanged(newConfig: Configuration) {
+          if (reactApplicationContext.hasActiveReactInstance()) {
+            updateAndSendBoldTextChangeEvent()
+          }
+        }
+
+        @Deprecated(
+            "onLowMemory is deprecated, use onTrimMemory instead.",
+            ReplaceWith("onTrimMemory(level)"),
+        )
+        override fun onLowMemory(): Unit = Unit
+      }
+  private var boldTextCallbacksRegistered = false
   private val accessibilityManager: AccessibilityManager?
   private val touchExplorationStateChangeListener: ReactTouchExplorationStateChangeListener =
       ReactTouchExplorationStateChangeListener()
@@ -80,6 +98,7 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
   private val contentResolver: ContentResolver
   private var reduceMotionEnabled = false
   private var highTextContrastEnabled = false
+  private var boldTextEnabled = false
   private var touchExplorationEnabled = false
   private var accessibilityServiceEnabled = false
   private var recommendedTimeout = 0
@@ -95,6 +114,7 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
     accessibilityServiceEnabled = accessibilityManager?.isEnabled ?: false
     reduceMotionEnabled = isReduceMotionEnabledValue
     highTextContrastEnabled = isHighTextContrastEnabledValue
+    boldTextEnabled = isBoldTextEnabledValue
     grayscaleModeEnabled = isGrayscaleEnabledValue
   }
 
@@ -154,6 +174,11 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
       ) != 0
     }
 
+  private val isBoldTextEnabledValue: Boolean
+    get() =
+        Build.VERSION.SDK_INT >= Build.VERSION_CODES.S &&
+            isBoldTextEnabled(reactApplicationContext.resources.configuration.fontWeightAdjustment)
+
   override fun isReduceMotionEnabled(successCallback: Callback) {
     successCallback.invoke(reduceMotionEnabled)
   }
@@ -170,6 +195,10 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
     successCallback.invoke(highTextContrastEnabled)
   }
 
+  override fun isBoldTextEnabled(successCallback: Callback) {
+    successCallback.invoke(boldTextEnabled)
+  }
+
   override fun isTouchExplorationEnabled(successCallback: Callback) {
     successCallback.invoke(touchExplorationEnabled)
   }
@@ -208,6 +237,15 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
     }
   }
 
+  private fun updateAndSendBoldTextChangeEvent() {
+    val isBoldTextEnabled = isBoldTextEnabledValue
+    if (boldTextEnabled != isBoldTextEnabled) {
+      boldTextEnabled = isBoldTextEnabled
+      getReactApplicationContextIfActiveOrWarn()
+          ?.emitDeviceEvent(BOLD_TEXT_EVENT_NAME, boldTextEnabled)
+    }
+  }
+
   private fun updateAndSendTouchExplorationChangeEvent(enabled: Boolean) {
     if (touchExplorationEnabled != enabled) {
       touchExplorationEnabled = enabled
@@ -243,12 +281,17 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
     val highTextContrastUri =
         Settings.Secure.getUriFor(ACCESSIBILITY_HIGH_TEXT_CONTRAST_ENABLED_CONSTANT)
     contentResolver.registerContentObserver(highTextContrastUri, false, highTextContrastObserver)
+    if (!boldTextCallbacksRegistered) {
+      reactApplicationContext.applicationContext.registerComponentCallbacks(boldTextCallbacks)
+      boldTextCallbacksRegistered = true
+    }
     updateAndSendTouchExplorationChangeEvent(
         accessibilityManager?.isTouchExplorationEnabled == true,
     )
     updateAndSendAccessibilityServiceChangeEvent(accessibilityManager?.isEnabled == true)
     updateAndSendReduceMotionChangeEvent()
     updateAndSendHighTextContrastChangeEvent()
+    updateAndSendBoldTextChangeEvent()
     updateAndSendInvertColorsChangeEvent()
     updateAndSendGrayscaleModeChangeEvent()
   }
@@ -260,6 +303,14 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
     accessibilityManager?.removeAccessibilityStateChangeListener(accessibilityServiceChangeListener)
     contentResolver.unregisterContentObserver(animationScaleObserver)
     contentResolver.unregisterContentObserver(highTextContrastObserver)
+    unregisterBoldTextCallbacks()
+  }
+
+  private fun unregisterBoldTextCallbacks() {
+    if (boldTextCallbacksRegistered) {
+      reactApplicationContext.applicationContext.unregisterComponentCallbacks(boldTextCallbacks)
+      boldTextCallbacksRegistered = false
+    }
   }
 
   override fun initialize() {
@@ -270,10 +321,12 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
     updateAndSendAccessibilityServiceChangeEvent(accessibilityManager?.isEnabled == true)
     updateAndSendReduceMotionChangeEvent()
     updateAndSendHighTextContrastChangeEvent()
+    updateAndSendBoldTextChangeEvent()
   }
 
   override fun invalidate() {
     reactApplicationContext.removeLifecycleEventListener(this)
+    unregisterBoldTextCallbacks()
     super.invalidate()
   }
 
@@ -318,5 +371,14 @@ internal class AccessibilityInfoModule(context: ReactApplicationContext) :
         "high_text_contrast_enabled" // constant is marked with @hide
     private const val INVERT_COLOR_EVENT_NAME = "invertColorDidChange"
     private const val GRAYSCALE_MODE_EVENT_NAME = "grayscaleModeDidChange"
+    private const val BOLD_TEXT_EVENT_NAME = "boldTextDidChange"
+
+    /**
+     * Bold text raises the font weight adjustment. A negative adjustment means lighter text, and
+     * [Configuration.FONT_WEIGHT_ADJUSTMENT_UNDEFINED] means the value is not known.
+     */
+    internal fun isBoldTextEnabled(fontWeightAdjustment: Int): Boolean =
+        fontWeightAdjustment != Configuration.FONT_WEIGHT_ADJUSTMENT_UNDEFINED &&
+            fontWeightAdjustment > 0
   }
 }
diff --git a/...src/test/java/com/facebook/react/modules/accessibilityinfo/AccessibilityInfoModuleTest.kt b/...src/test/java/com/facebook/react/modules/accessibilityinfo/AccessibilityInfoModuleTest.kt
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.modules.accessibilityinfo
+
+import android.content.res.Configuration
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+
+class AccessibilityInfoModuleTest {
+  @Test
+  fun boldTextIsEnabledForAPositiveFontWeightAdjustment() {
+    assertThat(AccessibilityInfoModule.isBoldTextEnabled(300)).isTrue()
+  }
+
+  @Test
+  fun boldTextIsDisabledWithoutAFontWeightAdjustment() {
+    assertThat(AccessibilityInfoModule.isBoldTextEnabled(0)).isFalse()
+  }
+
+  @Test
+  fun boldTextIsDisabledForANegativeFontWeightAdjustment() {
+    assertThat(AccessibilityInfoModule.isBoldTextEnabled(-100)).isFalse()
+  }
+
+  @Test
+  fun boldTextIsDisabledWhenTheFontWeightAdjustmentIsUndefined() {
+    assertThat(
+            AccessibilityInfoModule.isBoldTextEnabled(
+                Configuration.FONT_WEIGHT_ADJUSTMENT_UNDEFINED
+            )
+        )
+        .isFalse()
+  }
+}