iPhone screen keeps dimming? 7 settings to check

2 min read · 7 steps · Updated 2 October 2026

Short answer

Open Settings, tap Accessibility, tap Display & Text Size, scroll to the bottom and switch off Auto-Brightness. If the screen still dims, check True Tone and Night Shift under Display & Brightness, and let the iPhone cool down: a hot iPhone lowers the brightness to protect itself.

An iPhone screen that gets darker on its own is nearly always doing what it was set up to do. Several features change the brightness or the colour without asking, and each has its own switch.

Menu names are from recent versions of iOS. On older versions a few entries have slightly different names, which are given in the steps.

Step by step

  1. Switch off Auto-Brightness

    Open Settings, Accessibility, Display & Text Size and scroll to the bottom. Auto-Brightness is on by default: a sensor lowers the brightness in dark places and raises it in bright ones. Step by step: how to turn off auto-brightness on an iPhone.

  2. Set the brightness by hand

    Open Control Center and drag the brightness bar up, or use the slider under Settings, Display & Brightness.

  3. Check True Tone

    Under Settings, Display & Brightness, True Tone adjusts colour and intensity to the light around you. Switch it off for a test if the screen seems to change by itself.

  4. Check Night Shift

    Under Settings, Display & Brightness, Night Shift, the display turns warmer in the evening, which can look dimmer. Switch off the schedule if you do not want it.

  5. Let the iPhone cool down

    When an iPhone gets too hot, it dims the display. Take it out of the sun, remove the case and stop charging for a while.

  6. Check Low Power Mode

    Low Power Mode reduces display brightness and locks the screen sooner. Under Settings, Battery you can switch it off. More in how to turn on Low Power Mode on an iPhone.

  7. Check the Always-On display and Auto-Lock

    On models with an Always-On display, the screen dims when the iPhone is locked or idle. That is normal. Under Settings, Display & Brightness, Auto-Lock you set how long the screen stays fully bright before it locks.

Good to know

The screen also dims for a moment just before it locks. If you are reading and it dims, tap the screen once.

Reduce White Point under Accessibility, Display & Text Size makes the whole screen darker. Make sure it is off.

A screen that flickers or stays dark at full brightness after all of these checks needs a look by Apple or a repair shop.

In short: Auto-Brightness off, brightness by hand, True Tone, Night Shift, cool down, Low Power Mode, Always-On display and Auto-Lock.

Sources
  • Apple Support: Adjust the brightness and color temperature on your iPhone or iPad

Rules and prices change. Check the official source before you act.