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Does your iPhone screen keep going dark or turning off while reading something, checking a shopping list, or any other time you don’t want it to? There’s an easy way to fix that in Settings. Here’s how.

The reason your iPhone keeps dimming and turning off is because of a feature called “Auto-Lock,” which automatically puts the iPhone into a sleep/lock mode after a certain period of time. Two-thirds of the way through the set period, the screen dims to half brightness. To fix it, we need to turn “Auto-Lock” off.

First, open the “Settings” app by tapping the “gear” icon.

Open Settings on iPhone

In “Settings,” tap “Display & Brightness.”

Tap "Display & Brightness" in iPhone Settings.

In “Display & Brightness” settings, scroll down and tap “Auto-Lock.”

(Note: If you have Low Power mode enabled, Auto-Lock will be set to “30 Seconds,” and you won’t be able to tap on the option to change it. To change it, first disable Low Power mode.)

Tap "Auto-Lock" in "Display & Brightness" in iPhone Settings.


In “Auto-Lock,” you will see a list of time options. These determine the length of time your iPhone’s screen will stay lit before turning off and going into Lock mode.

Here, we’re going to turn it off entirely, so select “Never.”

Tap "Never" in "Auto-Lock" settings in iPhone Settings.

After that, exit “Settings.” Whenever you wake your iPhone, its screen will stay lit and will not go into Lock mode until you push the power button.

If you keep having trouble with a dimming screen even with “Auto-Lock” disabled, it could be because “Auto-Brightness” is enabled. “Auto-Brightness” can be disabled under the Accessibility options in the Settings app.

RELATED: How to Disable Auto-Brightness on Your iPhone

It’s Usually Best to Reenable Auto-Lock Again Later

There are some drawbacks to disabling “Auto-Lock.” The first is battery life: Your phone will run out of battery charge much faster if you forget to turn the screen off. The second is security: If you leave your phone on and it does not lock automatically, anyone can potentially use it.

So, it might be best to turn the “Auto-Lock” feature back on when you’re done. To do that, just repeat the steps above and select a time limit from the list instead of “Never.” Good luck!

RELATED: 8 Tips for Saving Battery Life on Your iPhone

Benj Edwards Benj Edwards
Benj Edwards is an Associate Editor for How-To Geek. For over 15 years, he has written about technology and tech history for sites such as The Atlantic, Fast Company, PCMag, PCWorld, Macworld, Ars Technica, and Wired. In 2005, he created Vintage Computing and Gaming, a blog devoted to tech history. He also created The Culture of Tech podcast and regularly contributes to the Retronauts retrogaming podcast.
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