Your iPhone’s “sleep mode” for the screen is called Auto-Lock. To change it, open Settings > Display & Brightness > Auto-Lock and choose how long the screen stays on before it turns off and locks. A short time, such as 30 seconds or 1 minute, saves the most battery. On iPhone Pro models, turning off Always On Display saves more, and the Sleep Focus silences the phone overnight.
Applies to: iPhone with iOS 26 or iOS 18. The settings are in the same places on recent older versions. Last reviewed October 7, 2026.
Change the Auto-Lock time
- Open Settings.
- Tap Display & Brightness.
- Tap Auto-Lock.
- Choose 30 seconds, 1 minute, 2, 3, 4 or 5 minutes, or Never.
The screen stays on for that long after you last touch it, then turns off and locks. Never keeps the screen on until you press the side button, which drains the battery quickly and leaves your iPhone unlocked if you put it down. Use it only for short tasks, such as following a recipe, and change it back afterward.
Auto-Lock is greyed out
Low Power Mode is on, and it fixes Auto-Lock at 30 seconds. Turn it off in Settings > Battery > Low Power Mode to choose a different time. A work or school profile can also lock this setting.
Turn off Always On Display
iPhone 14 Pro and later Pro models, and some newer standard models, can keep a dimmed lock screen visible all the time. It’s efficient, but turning it off still saves some battery.
- Open Settings > Display & Brightness.
- Tap Always On Display and turn it off. Or keep it on and turn off Show Wallpaper and Show Notifications for a darker, simpler display.
Keep the screen from dimming while you look at it
iPhones with Face ID can stay awake while you’re looking at them. Open Settings > Face ID & Passcode and turn on Attention Aware Features. Your iPhone then won’t dim or lock while you’re reading, even with a short Auto-Lock time.
Use Low Power Mode when the battery is low
Low Power Mode reduces background activity, sets Auto-Lock to 30 seconds and lowers some visual effects.
- Turn it on in Settings > Battery > Low Power Mode, or add the Low Power Mode button to Control Center.
- Your iPhone offers to turn it on at 20% battery, and it turns off automatically once the iPhone charges above 80%.
Newer iPhones with iOS 26 also offer Adaptive Power in Settings > Battery > Power Mode, which makes small adjustments automatically when you’re using more battery than usual.
Set up the Sleep Focus for bedtime
If by “sleep mode” you mean a mode for overnight, use the Sleep Focus. It silences calls and notifications and dims the lock screen while you sleep.
- Open Settings > Focus > Sleep.
- Choose people and apps that are allowed to reach you, such as family or alarms.
- Under Set a Schedule, add your bedtime, or set it in the Health app under Sleep > Full Schedule & Options.
Alarms still go off in Sleep Focus. To quiet calls from unknown numbers at any time, see how to silence unknown callers on an iPhone.
More ways to save battery
- Lower the brightness: swipe down from the top-right corner and drag the brightness slider down. Keep Auto-Brightness on in Settings > Accessibility > Display & Text Size.
- Use Dark Mode: on iPhones with OLED screens, dark backgrounds use less power. Turn it on in Display & Brightness.
- Check what’s using battery: Settings > Battery lists which apps used the most.
- Check battery health: Settings > Battery > Battery Health. A low maximum capacity means a replacement battery would help more than any setting.
Frequently asked questions
Does a shorter Auto-Lock really save battery?
Yes. The screen is one of the biggest power users, so cutting minutes of screen-on time each day adds up.
Why does my iPhone screen turn off while I’m reading?
Auto-Lock is set short and Attention Aware Features is off, or Low Power Mode is on. Change either setting above.
Can I set a different Auto-Lock time for one app?
No. Auto-Lock applies to the whole iPhone. Some apps, such as video players and navigation apps, keep the screen on by themselves while they’re in use.
Related: how to stop your iPhone screen from turning off.
Related: how to change the date and time on an iPhone.
Related: how to enable Low Power Mode quickly on an iPhone.
Related: how to make an iphone 15 screen turn off.
Related: how to turn off auto-brightness on iphone 15.
Related: why your iPhone battery icon is yellow.
Related: how to turn off Attention Aware features on iPhone.
Matt Jacobs has been working as an IT consultant for small businesses since receiving his Master’s degree in 2003. While he still does some consulting work, his primary focus now is on creating technology support content for SupportYourTech.com.
His work can be found on many websites and focuses on topics such as Microsoft Office, Apple devices, Android devices, Photoshop, and more.