How to Enable or Disable Auto-Brightness on iPhone?

By default, the auto-brightness feature is enabled on your iPhone.

If you want to disable it, here are the steps (here, I’m using iPhone X (iOS 13.3)):

Open Settings.

Hit Accessibility which you can find between Display & Brightness and Wallpaper.

Accessibility

Tap Display & Text Size which you can find between Magnifier and Motion.

Display & Text Size

Now scroll down to the bottom. Hit the toggle switch beside Auto-Brightness, which you can find beneath Reduce White Point.

Disabled Auto-Brightness

Note: you can follow the above steps to enable the auto-brightness feature.

That’s all.