How to Fix Auto Brightness in iPhone [Troubleshooting Guide]

Is your iPhone screen randomly dimming or changing brightness on its own? This frustrating issue is common, but fortunately there are ways to fix it.

In this guide, we’ll walk you through the top reasons your iPhone screen may be dimming and how to troubleshoot each one. Follow our step-by-step instructions to resolve auto-brightness problems and get your iPhone display back to normal. Here’s how to fix auto brightness in iPhone:

Disable Auto-Brightness

The most common culprit behind erratic screen brightness is the Auto-Brightness feature. This uses ambient light sensors to automatically adjust screen brightness based on your environment.

While helpful in theory, Auto-Brightness can sometimes misjudge lighting conditions and make your screen too dark. Here’s how to turn it off:

Open the Settings app on your iPhone.
Tap Accessibility.
Select Display & Text Size.
Scroll down and toggle the Auto-Brightness switch off (gray).

With this setting disabled, your iPhone will maintain a consistent brightness level rather than changing it automatically.

Turn Off True Tone

True Tone is another iPhone feature that modifies display settings based on ambient light. It adjusts color temperature to make the screen more natural and comfortable on your eyes.

But it can also unintentionally make your iPhone dimmer in certain conditions. To see if True Tone is the issue:

Go to Settings > Display & Brightness.
Turn the True Tone switch off.

Monitor your display for a while after disabling True Tone. If the random dimming stops, you’ve likely found the culprit.

Don’t Let Your iPhone Overheat

Excessive heat is a common cause of iPhone screen problems, including automatic dimming. Here are some tips to prevent overheating:

Avoid leaving your iPhone in hot areas like direct sunlight or closed cars.
Close resource-intensive apps when not in use.
Avoid using iPhone charging cases as they can trap heat.
Update to the latest iOS version to fix potential software bugs.
Consider turning on Low Power Mode which reduces system strain.

If your iPhone is very hot and displaying an overheating warning, shut it down and let it cool completely before using again. Persistent overheating may indicate a hardware defect needing repair.

Check Your Screen Auto-Lock Setting

The Auto-Lock feature dimming your display right before the screen shuts off is normal. But if it’s happening too frequently, adjust the auto-lock time:

Go to Settings > Display & Brightness.
Tap Auto-Lock.
Increase the time before auto-lock (e.g. 5 minutes).

A longer auto-lock duration reduces unwanted screen dimming. Just keep in mind it will use more battery power.

Disable Dark Mode

While Dark Mode doesn’t directly affect brightness levels, it makes your iPhone interface darker for comfort in low-light conditions. If Dark Mode is enabled, try turning it off to see if it’s contributing to a dim look:

Go to Settings > Display & Brightness.
Tap the Dark Mode option.
Select the Light appearance instead.

With Dark Mode disabled, your screen will look brighter overall. You can always re-enable it later on if needed.

Turn Off Reduce White Point

The Reduce White Point accessibility feature lowers brightness and color intensity. If enabled, screen dimming will occur constantly.

To check if Reduce White Point is on:

Go to Settings > Accessibility.
Select Display & Text Size.
Look under Color Filters for the Reduce White Point switch.
Turn Reduce White Point off if enabled.

This will return your iPhone display to its full color gamut and brightness capacity if it was the culprit.

Reset All Settings

If you can’t pinpoint the specific setting causing auto-brightness issues, reset your iPhone to factory default settings:

Go to Settings > General > Reset.
Tap Reset All Settings (this won’t erase data).
Enter your passcode if prompted.
Confirm resetting all settings when asked.

Once your iPhone restarts, all settings like Auto-Brightness and Dark Mode will be at their default values, which may resolve erratic screen dimming.

Contact Apple Support

For persistent auto-brightness problems not fixed by our troubleshooting, reach out to Apple support:

Book a Genius Bar appointment at an Apple Store for in-person iPhone diagnostics.
Contact Apple support by phone or chat to run tests and advanced troubleshooting.
Mail your iPhone to Apple for inspection and repair if covered under warranty or AppleCare.

Apple can run diagnostics to determine if your issues stem from a hardware defect or other problem requiring service.

With a few targeted settings changes, you should be able to stop annoying auto-brightness behavior and get consistent lighting on your iPhone screen. Pay special attention to Auto-Brightness, True Tone, Overheating, and Reduce White Point as common culprits behind this problem. But if issues continue, don’t hesitate to contact Apple for assistance identifying any underlying hardware or software issues.