Most of the time, your iPhone keeps dimming because Auto-Brightness is turned on. ... You'll have to turn off Auto-Brightness if your iPhone keeps dimming and you want it to stop. Open Settings and tap Accessibility -> Display & Text Size. Then, turn off the switch next to Auto-Brightness.

Why is my screen so dark on full brightness?

Assuming your display isn't damaged, the most common culprit for a consistently darkened screen is power saving mode. When your battery is close to being drained, your smartphone can turn off a number of background operations and tweak the display to use less power.

Why is my iPhone screen so dim?

You can adjust the brightness of your iPhone in Control Center. ... Open Settings and tap Display & Brightness. Drag the slider under Brightness to the right to increase the brightness of your iPhone. If your iPhone is still too dark, it's time to look at a new setting that Apple introduced with iOS 10: Reduce White Point.