diff --git a/services/core/java/com/android/server/input/InputFeatureFlagProvider.java b/services/core/java/com/android/server/input/InputFeatureFlagProvider.java
new file mode 100644
index 0000000..3854ada
--- /dev/null
+++ b/services/core/java/com/android/server/input/InputFeatureFlagProvider.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.input;
+
+import android.sysprop.InputProperties;
+
+import java.util.Optional;
+
+/**
+ * A component of {@link InputManagerService} responsible for managing the input sysprop flags
+ *
+ * @hide
+ */
+@SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+public final class InputFeatureFlagProvider {
+
+    // To disable Keyboard backlight control via Framework, run:
+    // 'adb shell setprop persist.input.keyboard_backlight_control.enabled false' (requires restart)
+    private static final boolean KEYBOARD_BACKLIGHT_CONTROL_ENABLED =
+            InputProperties.enable_keyboard_backlight_control().orElse(true);
+
+    // To disable Framework controlled keyboard backlight animation run:
+    // adb shell setprop persist.input.keyboard.backlight_animation.enabled false (requires restart)
+    private static final boolean KEYBOARD_BACKLIGHT_ANIMATION_ENABLED =
+            InputProperties.enable_keyboard_backlight_animation().orElse(false);
+
+    private static Optional<Boolean> sKeyboardBacklightControlOverride = Optional.empty();
+    private static Optional<Boolean> sKeyboardBacklightAnimationOverride = Optional.empty();
+
+    public static boolean isKeyboardBacklightControlEnabled() {
+        return sKeyboardBacklightControlOverride.orElse(KEYBOARD_BACKLIGHT_CONTROL_ENABLED);
+    }
+
+    public static boolean isKeyboardBacklightAnimationEnabled() {
+        return sKeyboardBacklightAnimationOverride.orElse(KEYBOARD_BACKLIGHT_ANIMATION_ENABLED);
+    }
+
+    public static void setKeyboardBacklightControlEnabled(boolean enabled) {
+        sKeyboardBacklightControlOverride = Optional.of(enabled);
+    }
+
+    public static void setKeyboardBacklightAnimationEnabled(boolean enabled) {
+        sKeyboardBacklightAnimationOverride = Optional.of(enabled);
+    }
+
+    /**
+     * Clears all input feature flag overrides.
+     */
+    public static void clearOverrides() {
+        sKeyboardBacklightControlOverride = Optional.empty();
+        sKeyboardBacklightAnimationOverride = Optional.empty();
+    }
+}
diff --git a/services/core/java/com/android/server/input/InputManagerService.java b/services/core/java/com/android/server/input/InputManagerService.java
index 662591e..9f3ab88 100644
--- a/services/core/java/com/android/server/input/InputManagerService.java
+++ b/services/core/java/com/android/server/input/InputManagerService.java
@@ -74,7 +74,6 @@
 import android.os.RemoteException;
 import android.os.ResultReceiver;
 import android.os.ShellCallback;
-import android.os.SystemProperties;
 import android.os.UserHandle;
 import android.os.VibrationEffect;
 import android.os.vibrator.StepSegment;
@@ -160,11 +159,6 @@
     private static final AdditionalDisplayInputProperties
             DEFAULT_ADDITIONAL_DISPLAY_INPUT_PROPERTIES = new AdditionalDisplayInputProperties();
 
-    // To disable Keyboard backlight control via Framework, run:
-    // 'adb shell setprop persist.input.keyboard_backlight_control.enabled false' (requires restart)
-    private static final boolean KEYBOARD_BACKLIGHT_CONTROL_ENABLED = SystemProperties.getBoolean(
-            "persist.input.keyboard.backlight_control.enabled", true);
-
     private final NativeInputManagerService mNative;
 
     private final Context mContext;
@@ -439,10 +433,9 @@
         mKeyboardLayoutManager = new KeyboardLayoutManager(mContext, mNative, mDataStore,
                 injector.getLooper());
         mBatteryController = new BatteryController(mContext, mNative, injector.getLooper());
-        mKeyboardBacklightController =
-                KEYBOARD_BACKLIGHT_CONTROL_ENABLED ? new KeyboardBacklightController(mContext,
-                        mNative, mDataStore, injector.getLooper())
-                        : new KeyboardBacklightControllerInterface() {};
+        mKeyboardBacklightController = InputFeatureFlagProvider.isKeyboardBacklightControlEnabled()
+                ? new KeyboardBacklightController(mContext, mNative, mDataStore,
+                injector.getLooper()) : new KeyboardBacklightControllerInterface() {};
         mKeyRemapper = new KeyRemapper(mContext, mNative, mDataStore, injector.getLooper());
 
         mUseDevInputEventForAudioJack =
diff --git a/services/core/java/com/android/server/input/KeyboardBacklightController.java b/services/core/java/com/android/server/input/KeyboardBacklightController.java
index 48c346a..61ca0cb 100644
--- a/services/core/java/com/android/server/input/KeyboardBacklightController.java
+++ b/services/core/java/com/android/server/input/KeyboardBacklightController.java
@@ -16,6 +16,7 @@
 
 package com.android.server.input;
 
+import android.animation.ValueAnimator;
 import android.annotation.BinderThread;
 import android.content.Context;
 import android.graphics.Color;
@@ -70,6 +71,8 @@
     private static final int MSG_INTERACTIVE_STATE_CHANGED = 6;
     private static final int MAX_BRIGHTNESS = 255;
     private static final int NUM_BRIGHTNESS_CHANGE_STEPS = 10;
+    private static final long TRANSITION_ANIMATION_DURATION_MILLIS =
+            Duration.ofSeconds(1).toMillis();
 
     private static final String UEVENT_KEYBOARD_BACKLIGHT_TAG = "kbd_backlight";
 
@@ -85,6 +88,7 @@
     @GuardedBy("mDataStore")
     private final PersistentDataStore mDataStore;
     private final Handler mHandler;
+    private final AnimatorFactory mAnimatorFactory;
     // Always access on handler thread or need to lock this for synchronization.
     private final SparseArray<KeyboardBacklightState> mKeyboardBacklights = new SparseArray<>(1);
     // Maintains state if all backlights should be on or turned off
@@ -109,10 +113,17 @@
 
     KeyboardBacklightController(Context context, NativeInputManagerService nativeService,
             PersistentDataStore dataStore, Looper looper) {
+        this(context, nativeService, dataStore, looper, ValueAnimator::ofInt);
+    }
+
+    @VisibleForTesting
+    KeyboardBacklightController(Context context, NativeInputManagerService nativeService,
+            PersistentDataStore dataStore, Looper looper, AnimatorFactory animatorFactory) {
         mContext = context;
         mNative = nativeService;
         mDataStore = dataStore;
         mHandler = new Handler(looper, this::handleMessage);
+        mAnimatorFactory = animatorFactory;
     }
 
     @Override
@@ -177,8 +188,7 @@
         } else {
             newBrightnessLevel = Math.max(currBrightnessLevel - 1, 0);
         }
-        updateBacklightState(deviceId, keyboardBacklight, newBrightnessLevel,
-                true /* isTriggeredByKeyPress */);
+        updateBacklightState(deviceId, newBrightnessLevel, true /* isTriggeredByKeyPress */);
 
         synchronized (mDataStore) {
             try {
@@ -203,8 +213,7 @@
             if (index < 0) {
                 index = Math.min(NUM_BRIGHTNESS_CHANGE_STEPS, -(index + 1));
             }
-            updateBacklightState(inputDevice.getId(), keyboardBacklight, index,
-                    false /* isTriggeredByKeyPress */);
+            updateBacklightState(inputDevice.getId(), index, false /* isTriggeredByKeyPress */);
             if (DEBUG) {
                 Slog.d(TAG, "Restoring brightness level " + brightness.getAsInt());
             }
@@ -217,14 +226,10 @@
         if (!mIsInteractive) {
             return;
         }
-        if (!mIsBacklightOn) {
-            mIsBacklightOn = true;
-            for (int i = 0; i < mKeyboardBacklights.size(); i++) {
-                int deviceId = mKeyboardBacklights.keyAt(i);
-                KeyboardBacklightState state = mKeyboardBacklights.valueAt(i);
-                updateBacklightState(deviceId, state.mLight, state.mBrightnessLevel,
-                        false /* isTriggeredByKeyPress */);
-            }
+        mIsBacklightOn = true;
+        for (int i = 0; i < mKeyboardBacklights.size(); i++) {
+            KeyboardBacklightState state = mKeyboardBacklights.valueAt(i);
+            state.onBacklightStateChanged();
         }
         mHandler.removeMessages(MSG_NOTIFY_USER_INACTIVITY);
         mHandler.sendEmptyMessageAtTime(MSG_NOTIFY_USER_INACTIVITY,
@@ -232,14 +237,10 @@
     }
 
     private void handleUserInactivity() {
-        if (mIsBacklightOn) {
-            mIsBacklightOn = false;
-            for (int i = 0; i < mKeyboardBacklights.size(); i++) {
-                int deviceId = mKeyboardBacklights.keyAt(i);
-                KeyboardBacklightState state = mKeyboardBacklights.valueAt(i);
-                updateBacklightState(deviceId, state.mLight, state.mBrightnessLevel,
-                        false /* isTriggeredByKeyPress */);
-            }
+        mIsBacklightOn = false;
+        for (int i = 0; i < mKeyboardBacklights.size(); i++) {
+            KeyboardBacklightState state = mKeyboardBacklights.valueAt(i);
+            state.onBacklightStateChanged();
         }
     }
 
@@ -310,7 +311,7 @@
             return;
         }
         // The keyboard backlight was added or changed.
-        mKeyboardBacklights.put(deviceId, new KeyboardBacklightState(keyboardBacklight));
+        mKeyboardBacklights.put(deviceId, new KeyboardBacklightState(deviceId, keyboardBacklight));
         restoreBacklightBrightness(inputDevice, keyboardBacklight);
     }
 
@@ -372,21 +373,14 @@
         }
     }
 
-    private void updateBacklightState(int deviceId, Light light, int brightnessLevel,
+    private void updateBacklightState(int deviceId, int brightnessLevel,
             boolean isTriggeredByKeyPress) {
         KeyboardBacklightState state = mKeyboardBacklights.get(deviceId);
         if (state == null) {
             return;
         }
 
-        mNative.setLightColor(deviceId, light.getId(),
-                mIsBacklightOn ? Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[brightnessLevel], 0, 0, 0)
-                        : 0);
-        if (DEBUG) {
-            Slog.d(TAG, "Changing state from " + state.mBrightnessLevel + " to " + brightnessLevel
-                    + "(isBacklightOn = " + mIsBacklightOn + ")");
-        }
-        state.mBrightnessLevel = brightnessLevel;
+        state.setBrightnessLevel(brightnessLevel);
 
         synchronized (mKeyboardBacklightListenerRecords) {
             for (int i = 0; i < mKeyboardBacklightListenerRecords.size(); i++) {
@@ -397,6 +391,10 @@
                         deviceId, callbackState, isTriggeredByKeyPress);
             }
         }
+
+        if (DEBUG) {
+            Slog.d(TAG, "Changing state from " + state.mBrightnessLevel + " to " + brightnessLevel);
+        }
     }
 
     private void onKeyboardBacklightListenerDied(int pid) {
@@ -436,10 +434,7 @@
     @Override
     public void dump(PrintWriter pw) {
         IndentingPrintWriter ipw = new IndentingPrintWriter(pw);
-        ipw.println(
-                TAG + ": " + mKeyboardBacklights.size() + " keyboard backlights, isBacklightOn = "
-                        + mIsBacklightOn);
-
+        ipw.println(TAG + ": " + mKeyboardBacklights.size() + " keyboard backlights");
         ipw.increaseIndent();
         for (int i = 0; i < mKeyboardBacklights.size(); i++) {
             KeyboardBacklightState state = mKeyboardBacklights.valueAt(i);
@@ -448,6 +443,10 @@
         ipw.decreaseIndent();
     }
 
+    private static boolean isAnimationEnabled() {
+        return InputFeatureFlagProvider.isKeyboardBacklightAnimationEnabled();
+    }
+
     // A record of a registered Keyboard backlight listener from one process.
     private class KeyboardBacklightListenerRecord implements IBinder.DeathRecipient {
         public final int mPid;
@@ -478,14 +477,55 @@
         }
     }
 
-    private static class KeyboardBacklightState {
+    private class KeyboardBacklightState {
+        private final int mDeviceId;
         private final Light mLight;
         private int mBrightnessLevel;
+        private ValueAnimator mAnimator;
 
-        KeyboardBacklightState(Light light) {
+        KeyboardBacklightState(int deviceId, Light light) {
+            mDeviceId = deviceId;
             mLight = light;
         }
 
+        private void onBacklightStateChanged() {
+            setBacklightValue(mIsBacklightOn ? BRIGHTNESS_VALUE_FOR_LEVEL[mBrightnessLevel] : 0);
+        }
+        private void setBrightnessLevel(int brightnessLevel) {
+            if (mIsBacklightOn) {
+                setBacklightValue(BRIGHTNESS_VALUE_FOR_LEVEL[brightnessLevel]);
+            }
+            mBrightnessLevel = brightnessLevel;
+        }
+
+        private void cancelAnimation() {
+            if (mAnimator != null && mAnimator.isRunning()) {
+                mAnimator.cancel();
+            }
+        }
+
+        private void setBacklightValue(int toValue) {
+            int fromValue = Color.alpha(mNative.getLightColor(mDeviceId, mLight.getId()));
+            if (fromValue == toValue) {
+                return;
+            }
+            if (isAnimationEnabled()) {
+                startAnimation(fromValue, toValue);
+            } else {
+                mNative.setLightColor(mDeviceId, mLight.getId(), Color.argb(toValue, 0, 0, 0));
+            }
+        }
+
+        private void startAnimation(int fromValue, int toValue) {
+            // Cancel any ongoing animation before starting a new one
+            cancelAnimation();
+            mAnimator = mAnimatorFactory.makeIntAnimator(fromValue, toValue);
+            mAnimator.addUpdateListener(
+                    (animation) -> mNative.setLightColor(mDeviceId, mLight.getId(),
+                            Color.argb((int) animation.getAnimatedValue(), 0, 0, 0)));
+            mAnimator.setDuration(TRANSITION_ANIMATION_DURATION_MILLIS).start();
+        }
+
         @Override
         public String toString() {
             return "KeyboardBacklightState{Light=" + mLight.getId()
@@ -493,4 +533,9 @@
                     + "}";
         }
     }
+
+    @VisibleForTesting
+    interface AnimatorFactory {
+        ValueAnimator makeIntAnimator(int from, int to);
+    }
 }
diff --git a/services/tests/servicestests/src/com/android/server/input/KeyboardBacklightControllerTests.kt b/services/tests/servicestests/src/com/android/server/input/KeyboardBacklightControllerTests.kt
index 64c05dc..2726792 100644
--- a/services/tests/servicestests/src/com/android/server/input/KeyboardBacklightControllerTests.kt
+++ b/services/tests/servicestests/src/com/android/server/input/KeyboardBacklightControllerTests.kt
@@ -16,6 +16,7 @@
 
 package com.android.server.input
 
+import android.animation.ValueAnimator
 import android.content.Context
 import android.content.ContextWrapper
 import android.graphics.Color
@@ -29,6 +30,7 @@
 import android.os.test.TestLooper
 import android.platform.test.annotations.Presubmit
 import android.view.InputDevice
+import androidx.test.annotation.UiThreadTest
 import androidx.test.core.app.ApplicationProvider
 import com.android.server.input.KeyboardBacklightController.BRIGHTNESS_VALUE_FOR_LEVEL
 import com.android.server.input.KeyboardBacklightController.USER_INACTIVITY_THRESHOLD_MILLIS
@@ -96,9 +98,11 @@
     private lateinit var context: Context
     private lateinit var dataStore: PersistentDataStore
     private lateinit var testLooper: TestLooper
+    private val totalLevels = BRIGHTNESS_VALUE_FOR_LEVEL.size
     private var lightColorMap: HashMap<Int, Int> = HashMap()
     private var lastBacklightState: KeyboardBacklightState? = null
     private var sysfsNodeChanges = 0
+    private var lastAnimationValues = IntArray(2)
 
     @Before
     fun setup() {
@@ -115,8 +119,8 @@
             override fun finishWrite(fos: FileOutputStream?, success: Boolean) {}
         })
         testLooper = TestLooper()
-        keyboardBacklightController =
-            KeyboardBacklightController(context, native, dataStore, testLooper.looper)
+        keyboardBacklightController = KeyboardBacklightController(context, native, dataStore,
+                testLooper.looper, FakeAnimatorFactory())
         InputManagerGlobal.resetInstance(iInputManager)
         val inputManager = InputManager(context)
         `when`(context.getSystemService(eq(Context.INPUT_SERVICE))).thenReturn(inputManager)
@@ -125,6 +129,10 @@
             val args = it.arguments
             lightColorMap.put(args[1] as Int, args[2] as Int)
         }
+        `when`(native.getLightColor(anyInt(), anyInt())).thenAnswer {
+            val args = it.arguments
+            lightColorMap.getOrDefault(args[1] as Int, 0)
+        }
         lightColorMap.clear()
         `when`(native.sysfsNodeChanged(any())).then {
             sysfsNodeChanges++
@@ -138,271 +146,287 @@
 
     @Test
     fun testKeyboardBacklightIncrementDecrement() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
 
-        for (level in 1 until BRIGHTNESS_VALUE_FOR_LEVEL.size) {
+            for (level in 1 until totalLevels) {
+                incrementKeyboardBacklight(DEVICE_ID)
+                assertEquals(
+                    "Light value for level $level mismatched",
+                    Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[level], 0, 0, 0),
+                    lightColorMap[LIGHT_ID]
+                )
+                assertEquals(
+                    "Light value for level $level must be correctly stored in the datastore",
+                    BRIGHTNESS_VALUE_FOR_LEVEL[level],
+                    dataStore.getKeyboardBacklightBrightness(
+                            keyboardWithBacklight.descriptor,
+                            LIGHT_ID
+                    ).asInt
+                )
+            }
+
+            // Increment above max level
             incrementKeyboardBacklight(DEVICE_ID)
             assertEquals(
-                "Light value for level $level mismatched",
-                Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[level], 0, 0, 0),
+                "Light value for max level mismatched",
+                Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
                 lightColorMap[LIGHT_ID]
             )
             assertEquals(
-                "Light value for level $level must be correctly stored in the datastore",
-                BRIGHTNESS_VALUE_FOR_LEVEL[level],
+                "Light value for max level must be correctly stored in the datastore",
+                MAX_BRIGHTNESS,
                 dataStore.getKeyboardBacklightBrightness(
-                    keyboardWithBacklight.descriptor,
-                    LIGHT_ID
+                        keyboardWithBacklight.descriptor,
+                        LIGHT_ID
                 ).asInt
             )
-        }
 
-        // Increment above max level
-        incrementKeyboardBacklight(DEVICE_ID)
-        assertEquals(
-            "Light value for max level mismatched",
-            Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
-            lightColorMap[LIGHT_ID]
-        )
-        assertEquals(
-            "Light value for max level must be correctly stored in the datastore",
-            MAX_BRIGHTNESS,
-            dataStore.getKeyboardBacklightBrightness(
-                keyboardWithBacklight.descriptor,
-                LIGHT_ID
-            ).asInt
-        )
+            for (level in totalLevels - 2 downTo 0) {
+                decrementKeyboardBacklight(DEVICE_ID)
+                assertEquals(
+                    "Light value for level $level mismatched",
+                    Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[level], 0, 0, 0),
+                    lightColorMap[LIGHT_ID]
+                )
+                assertEquals(
+                    "Light value for level $level must be correctly stored in the datastore",
+                    BRIGHTNESS_VALUE_FOR_LEVEL[level],
+                    dataStore.getKeyboardBacklightBrightness(
+                            keyboardWithBacklight.descriptor,
+                            LIGHT_ID
+                    ).asInt
+                )
+            }
 
-        for (level in BRIGHTNESS_VALUE_FOR_LEVEL.size - 2 downTo 0) {
+            // Decrement below min level
             decrementKeyboardBacklight(DEVICE_ID)
             assertEquals(
-                "Light value for level $level mismatched",
-                Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[level], 0, 0, 0),
+                "Light value for min level mismatched",
+                Color.argb(0, 0, 0, 0),
                 lightColorMap[LIGHT_ID]
             )
             assertEquals(
-                "Light value for level $level must be correctly stored in the datastore",
-                BRIGHTNESS_VALUE_FOR_LEVEL[level],
+                "Light value for min level must be correctly stored in the datastore",
+                0,
                 dataStore.getKeyboardBacklightBrightness(
-                    keyboardWithBacklight.descriptor,
-                    LIGHT_ID
+                        keyboardWithBacklight.descriptor,
+                        LIGHT_ID
                 ).asInt
             )
         }
-
-        // Decrement below min level
-        decrementKeyboardBacklight(DEVICE_ID)
-        assertEquals(
-            "Light value for min level mismatched",
-            Color.argb(0, 0, 0, 0),
-            lightColorMap[LIGHT_ID]
-        )
-        assertEquals(
-            "Light value for min level must be correctly stored in the datastore",
-            0,
-            dataStore.getKeyboardBacklightBrightness(
-                keyboardWithBacklight.descriptor,
-                LIGHT_ID
-            ).asInt
-        )
     }
 
     @Test
     fun testKeyboardWithoutBacklight() {
-        val keyboardWithoutBacklight = createKeyboard(DEVICE_ID)
-        val keyboardInputLight = createLight(LIGHT_ID, Light.LIGHT_TYPE_INPUT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithoutBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardInputLight))
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+        BacklightAnimationFlag(false).use {
+            val keyboardWithoutBacklight = createKeyboard(DEVICE_ID)
+            val keyboardInputLight = createLight(LIGHT_ID, Light.LIGHT_TYPE_INPUT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithoutBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardInputLight))
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
 
-        incrementKeyboardBacklight(DEVICE_ID)
-        assertTrue("Non Keyboard backlights should not change", lightColorMap.isEmpty())
+            incrementKeyboardBacklight(DEVICE_ID)
+            assertTrue("Non Keyboard backlights should not change", lightColorMap.isEmpty())
+        }
     }
 
     @Test
     fun testKeyboardWithMultipleLight() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        val keyboardInputLight = createLight(SECOND_LIGHT_ID, Light.LIGHT_TYPE_INPUT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(
-            listOf(
-                keyboardBacklight,
-                keyboardInputLight
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            val keyboardInputLight = createLight(SECOND_LIGHT_ID, Light.LIGHT_TYPE_INPUT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(
+                listOf(
+                    keyboardBacklight,
+                    keyboardInputLight
+                )
             )
-        )
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
 
-        incrementKeyboardBacklight(DEVICE_ID)
-        assertEquals("Only keyboard backlights should change", 1, lightColorMap.size)
-        assertNotNull("Keyboard backlight should change", lightColorMap[LIGHT_ID])
-        assertNull("Input lights should not change", lightColorMap[SECOND_LIGHT_ID])
+            incrementKeyboardBacklight(DEVICE_ID)
+            assertEquals("Only keyboard backlights should change", 1, lightColorMap.size)
+            assertNotNull("Keyboard backlight should change", lightColorMap[LIGHT_ID])
+            assertNull("Input lights should not change", lightColorMap[SECOND_LIGHT_ID])
+        }
     }
 
     @Test
     fun testRestoreBacklightOnInputDeviceAdded() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
 
-        for (level in 1 until BRIGHTNESS_VALUE_FOR_LEVEL.size) {
-            dataStore.setKeyboardBacklightBrightness(
+            for (level in 1 until totalLevels) {
+                dataStore.setKeyboardBacklightBrightness(
                     keyboardWithBacklight.descriptor,
                     LIGHT_ID,
                     BRIGHTNESS_VALUE_FOR_LEVEL[level] - 1
+                )
+
+                keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+                keyboardBacklightController.notifyUserActivity()
+                testLooper.dispatchNext()
+                assertEquals(
+                    "Keyboard backlight level should be restored to the level saved in the " +
+                            "data store",
+                    Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[level], 0, 0, 0),
+                    lightColorMap[LIGHT_ID]
+                )
+                keyboardBacklightController.onInputDeviceRemoved(DEVICE_ID)
+            }
+        }
+    }
+
+    @Test
+    fun testRestoreBacklightOnInputDeviceChanged() {
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            dataStore.setKeyboardBacklightBrightness(
+                keyboardWithBacklight.descriptor,
+                LIGHT_ID,
+                MAX_BRIGHTNESS
+            )
+
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+            keyboardBacklightController.notifyUserActivity()
+            testLooper.dispatchNext()
+            assertTrue(
+                "Keyboard backlight should not be changed until its added",
+                lightColorMap.isEmpty()
+            )
+
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+            keyboardBacklightController.onInputDeviceChanged(DEVICE_ID)
+            keyboardBacklightController.notifyUserActivity()
+            testLooper.dispatchNext()
+            assertEquals(
+                "Keyboard backlight level should be restored to the level saved in the data store",
+                Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
+                lightColorMap[LIGHT_ID]
+            )
+        }
+    }
+
+    @Test
+    fun testKeyboardBacklight_registerUnregisterListener() {
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+
+            // Register backlight listener
+            val listener = KeyboardBacklightListener()
+            keyboardBacklightController.registerKeyboardBacklightListener(listener, 0)
+
+            lastBacklightState = null
+            keyboardBacklightController.incrementKeyboardBacklight(DEVICE_ID)
+            testLooper.dispatchNext()
+
+            assertEquals(
+                "Backlight state device Id should be $DEVICE_ID",
+                DEVICE_ID,
+                lastBacklightState!!.deviceId
+            )
+            assertEquals(
+                "Backlight state brightnessLevel should be " + 1,
+                1,
+                lastBacklightState!!.brightnessLevel
+            )
+            assertEquals(
+                "Backlight state maxBrightnessLevel should be " + (totalLevels - 1),
+                (totalLevels - 1),
+                lastBacklightState!!.maxBrightnessLevel
+            )
+            assertEquals(
+                "Backlight state isTriggeredByKeyPress should be true",
+                true,
+                lastBacklightState!!.isTriggeredByKeyPress
+            )
+
+            // Unregister listener
+            keyboardBacklightController.unregisterKeyboardBacklightListener(listener, 0)
+
+            lastBacklightState = null
+            incrementKeyboardBacklight(DEVICE_ID)
+
+            assertNull("Listener should not receive any updates", lastBacklightState)
+        }
+    }
+
+    @Test
+    fun testKeyboardBacklight_userActivity() {
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+            dataStore.setKeyboardBacklightBrightness(
+                keyboardWithBacklight.descriptor,
+                LIGHT_ID,
+                MAX_BRIGHTNESS
             )
 
             keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
             keyboardBacklightController.notifyUserActivity()
             testLooper.dispatchNext()
             assertEquals(
-                    "Keyboard backlight level should be restored to the level saved in the data " +
-                            "store",
-                    Color.argb(BRIGHTNESS_VALUE_FOR_LEVEL[level], 0, 0, 0),
-                    lightColorMap[LIGHT_ID]
+                "Keyboard backlight level should be restored to the level saved in the data store",
+                Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
+                lightColorMap[LIGHT_ID]
             )
-            keyboardBacklightController.onInputDeviceRemoved(DEVICE_ID)
+
+            testLooper.moveTimeForward(USER_INACTIVITY_THRESHOLD_MILLIS + 1000)
+            testLooper.dispatchNext()
+            assertEquals(
+                "Keyboard backlight level should be turned off after inactivity",
+                0,
+                lightColorMap[LIGHT_ID]
+            )
         }
     }
 
     @Test
-    fun testRestoreBacklightOnInputDeviceChanged() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        dataStore.setKeyboardBacklightBrightness(
-            keyboardWithBacklight.descriptor,
-            LIGHT_ID,
-            MAX_BRIGHTNESS
-        )
-
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
-        keyboardBacklightController.notifyUserActivity()
-        testLooper.dispatchNext()
-        assertTrue(
-            "Keyboard backlight should not be changed until its added",
-            lightColorMap.isEmpty()
-        )
-
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
-        keyboardBacklightController.onInputDeviceChanged(DEVICE_ID)
-        keyboardBacklightController.notifyUserActivity()
-        testLooper.dispatchNext()
-        assertEquals(
-            "Keyboard backlight level should be restored to the level saved in the data store",
-            Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
-            lightColorMap[LIGHT_ID]
-        )
-    }
-
-    @Test
-    fun testKeyboardBacklight_registerUnregisterListener() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
-
-        // Register backlight listener
-        val listener = KeyboardBacklightListener()
-        keyboardBacklightController.registerKeyboardBacklightListener(listener, 0)
-
-        lastBacklightState = null
-        keyboardBacklightController.incrementKeyboardBacklight(DEVICE_ID)
-        testLooper.dispatchNext()
-
-        assertEquals(
-            "Backlight state device Id should be $DEVICE_ID",
-            DEVICE_ID,
-            lastBacklightState!!.deviceId
-        )
-        assertEquals(
-            "Backlight state brightnessLevel should be " + 1,
-            1,
-            lastBacklightState!!.brightnessLevel
-        )
-        assertEquals(
-            "Backlight state maxBrightnessLevel should be " + (BRIGHTNESS_VALUE_FOR_LEVEL.size - 1),
-            (BRIGHTNESS_VALUE_FOR_LEVEL.size - 1),
-            lastBacklightState!!.maxBrightnessLevel
-        )
-        assertEquals(
-            "Backlight state isTriggeredByKeyPress should be true",
-            true,
-            lastBacklightState!!.isTriggeredByKeyPress
-        )
-
-        // Unregister listener
-        keyboardBacklightController.unregisterKeyboardBacklightListener(listener, 0)
-
-        lastBacklightState = null
-        incrementKeyboardBacklight(DEVICE_ID)
-
-        assertNull("Listener should not receive any updates", lastBacklightState)
-    }
-
-    @Test
-    fun testKeyboardBacklight_userActivity() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
-        dataStore.setKeyboardBacklightBrightness(
-            keyboardWithBacklight.descriptor,
-            LIGHT_ID,
-            MAX_BRIGHTNESS
-        )
-
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
-        keyboardBacklightController.notifyUserActivity()
-        testLooper.dispatchNext()
-        assertEquals(
-            "Keyboard backlight level should be restored to the level saved in the data store",
-            Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
-            lightColorMap[LIGHT_ID]
-        )
-
-        testLooper.moveTimeForward(USER_INACTIVITY_THRESHOLD_MILLIS + 1000)
-        testLooper.dispatchNext()
-        assertEquals(
-            "Keyboard backlight level should be turned off after inactivity",
-            0,
-            lightColorMap[LIGHT_ID]
-        )
-    }
-
-    @Test
     fun testKeyboardBacklight_displayOnOff() {
-        val keyboardWithBacklight = createKeyboard(DEVICE_ID)
-        val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
-        `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
-        `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
-        dataStore.setKeyboardBacklightBrightness(
-            keyboardWithBacklight.descriptor,
-            LIGHT_ID,
-            MAX_BRIGHTNESS
-        )
+        BacklightAnimationFlag(false).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+            dataStore.setKeyboardBacklightBrightness(
+                keyboardWithBacklight.descriptor,
+                LIGHT_ID,
+                MAX_BRIGHTNESS
+            )
 
-        keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
-        keyboardBacklightController.handleInteractiveStateChange(true /* isDisplayOn */)
-        assertEquals(
-            "Keyboard backlight level should be restored to the level saved in the data " +
-                    "store when display turned on",
-            Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
-            lightColorMap[LIGHT_ID]
-        )
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+            keyboardBacklightController.handleInteractiveStateChange(true /* isDisplayOn */)
+            assertEquals(
+                "Keyboard backlight level should be restored to the level saved in the data " +
+                        "store when display turned on",
+                Color.argb(MAX_BRIGHTNESS, 0, 0, 0),
+                lightColorMap[LIGHT_ID]
+            )
 
-        keyboardBacklightController.handleInteractiveStateChange(false /* isDisplayOn */)
-        assertEquals(
-            "Keyboard backlight level should be turned off after display is turned off",
-            0,
-            lightColorMap[LIGHT_ID]
-        )
+            keyboardBacklightController.handleInteractiveStateChange(false /* isDisplayOn */)
+            assertEquals(
+                "Keyboard backlight level should be turned off after display is turned off",
+                0,
+                lightColorMap[LIGHT_ID]
+            )
+        }
     }
 
     @Test
@@ -463,6 +487,30 @@
         )
     }
 
+    @Test
+    @UiThreadTest
+    fun testKeyboardBacklightAnimation_onChangeLevels() {
+        BacklightAnimationFlag(true).use {
+            val keyboardWithBacklight = createKeyboard(DEVICE_ID)
+            val keyboardBacklight = createLight(LIGHT_ID, Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT)
+            `when`(iInputManager.getInputDevice(DEVICE_ID)).thenReturn(keyboardWithBacklight)
+            `when`(iInputManager.getLights(DEVICE_ID)).thenReturn(listOf(keyboardBacklight))
+            keyboardBacklightController.onInputDeviceAdded(DEVICE_ID)
+
+            incrementKeyboardBacklight(DEVICE_ID)
+            assertEquals(
+                "Should start animation from level 0",
+                BRIGHTNESS_VALUE_FOR_LEVEL[0],
+                lastAnimationValues[0]
+            )
+            assertEquals(
+                "Should start animation to level 1",
+                BRIGHTNESS_VALUE_FOR_LEVEL[1],
+                lastAnimationValues[1]
+            )
+        }
+    }
+
     inner class KeyboardBacklightListener : IKeyboardBacklightListener.Stub() {
         override fun onBrightnessChanged(
             deviceId: Int,
@@ -496,4 +544,22 @@
         val maxBrightnessLevel: Int,
         val isTriggeredByKeyPress: Boolean
     )
+
+    private inner class BacklightAnimationFlag constructor(enabled: Boolean) : AutoCloseable {
+        init {
+            InputFeatureFlagProvider.setKeyboardBacklightAnimationEnabled(enabled)
+        }
+
+        override fun close() {
+            InputFeatureFlagProvider.clearOverrides()
+        }
+    }
+
+    private inner class FakeAnimatorFactory : KeyboardBacklightController.AnimatorFactory {
+        override fun makeIntAnimator(from: Int, to: Int): ValueAnimator {
+            lastAnimationValues[0] = from
+            lastAnimationValues[1] = to
+            return ValueAnimator.ofInt(from, to)
+        }
+    }
 }