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How to fix Auto-Brightness Not Working on iPhone and Android screen changes automatically based on how bright it is where you are. For example, the brightness gets brighter when you go outside into the sun. And it gets less inside a room. When the auto-brightness feature on your iPhone doesn’t work, it can ruin your experience and even use more battery.
When you change the brightness slider by hand, Auto-Brightness uses machine learning on the device to learn your habits and adds them to the auto settings. Many people think that a feature that takes care of itself would be a great solution.
Fix Auto-Brightness Not Working on iPhone: 5 Simple Ways
Restore your iPhone
- Connect your iPhone to your computer via a compatible USB cable.
- Run iTunes and click on the iPhone device icon in the upper left corner of iTunes.
- Click “Summary” under the device icon from the menu on the left side.
- Tick the box for automatically backing up to “This computer“.
- Click “Restore Backup“. When the option appears, choose the latest iTunes backup and click “Restore“. If you have encrypted the iTunes backup, you need to enter the password to unlock the iPhone backup.
Reset All Settings on iPhone
If some mistakes in the iOS settings are causing your iPhone’s brightness not to work in iOS 11, you can try to fix the problem by resetting all of your iPhone’s settings. You won’t lose any data if you do this, so don’t worry about it. Go to “Settings” > “General” > “Reset” > “Reset All Settings”. Then, all of your iPhone’s settings will be erased, and you can set it up again to see what’s going on.
Turn Off/ On Auto-Brightness
- Open the Settings app on your iPhone and navigate to Accessibility -> Display & Text Size. Now, scroll down to the bottom and turn off the “Auto-Brightness” toggle.
- After that, restart your iPhone, and navigate to the same settings page in the step above. Then, turn on the Auto-Brightness toggle once again.
Remove the Screen Protector
Fix Auto-Brightness Not Working, Laser-cut sizes are not often found on screen guards (especially the cheaper ones). If the problem keeps coming back, it could be because of your screen guard. Once you’ve taken off the screen protector, check to see if the screen brightness changes automatically based on how bright it is where you are. If it does, it’s because of your screen protector, not your iPhone. Also, if you need a new screen protector.
Update Software on Your iPhone
Given how buggy the last few iOS updates have been, you should never say for sure that a software bug isn’t to blame for the ambient light sensor not working as it should. If that’s the case, it could be making your iPhone’s auto-brightness feature act up. So, if your iPhone’s auto-brightness keeps going wrong, you should update the iOS software.
Go to the Settings app on your iPhone and navigate to General -> Software Update. Then, download and install the latest version of iOS without any issues.

Fix Auto-Brightness Not Working on Android: 5 Simple Ways
Reset Adaptive Brightness
Resets have also worked wonders when fixing things that have gone haywire. To reset the adaptive brightness, you’ll need to go to Settings > Apps and notifications > See all x apps > Device Health Service > Storage and cache > Clear storage > Reset adaptive brightness.
Disable and Re-enable Automatic Brightness
- Open the Settings App on your Android phone.
- Scroll down to find Display and open it.
- Tap on the Brightness Level.
- Turn off the toggle for Automatic Brightness.
- Wait for a few seconds and then turn on the toggle for the Automatic Brightness feature.
- Alternatively, you can scroll down to access your notification panel and tap on the Auto-Brightness toggle to disable/enable it at any time.
Update Your Android Phone
- Open the Settings app on your phone.
- Tap on the About Phone option in the list.
- To manually check the phone for any updates, tap on the Check for Updates button.
- If your phone has received any new updates/bug fixes, then tap on the Download button to download and install it on your phone.
Restart/Reboot Your Android Device
When you install some third-party apps, they can sometimes temporarily change how your system works. This can cause the automatic brightness feature on your phone to stop working. This problem is easy to fix: just reboot or restart your phone. Follow these easy steps to restart your Android phone quickly.
- Long press the power button on your Android device till you see the Power Menu.
- Tap on the Reboot button to restart your phone.
Check the Light Sensor on Your Android
- Open the Google Play Store app, search for the Sensor Test app and install it.
- Provide the necessary access permissions to the app.
- Tap on the Test button in front of the Light Sensor.
- Move your phone to different lighting conditions and notice the value change in the app.
- If the value stays the same in all conditions, then it could indicate that your light sensor is damaged. You need to get it repaired by an authorized service center.
- If the value changes according to different lighting conditions, for example, more in brighter areas and less in darker areas, then your light sensor is working properly.
you can visit iPhone support center for further help.
FAQ
Why is my Android phone brightness not working
On Android: Settings > Display > Tap the button next to “Adaptive brightness” to turn it off. Then, move the brightness bar until the screen is as bright as you want it to be. Assuming your screen isn’t broken, power-saving mode is the most likely cause of a consistently dark screen. Jul 15, 2022
How do I test my auto brightness sensor
- Swipe down from the top of the screen to bring down the Notifications panel and then tap on the See More tab.
- Toggle the switch to enable Auto brightness.
- Go to the Settings menu > Display.
- Tap on Auto brightness.
- Toggle the switch to enable Auto brightness.
Why does brightness decrease automatically
Depending on how much light comes in through its sensors, your screen can be very bright or very dark. This keeps your phone from being too bright and wasting battery life unnecessarily. Some computers have this same technology built in.