How to change screen lock time on iPhone (Auto-Lock)
The setting is called Auto-Lock. If it is greyed out or stuck at 30 seconds, Low Power Mode is usually the reason.

Photo by Amanz on Unsplash
Apple does not call it screen lock time. The setting is named Auto-Lock, and it decides how long your iPhone screen stays on before it turns off and locks. If you searched for the lock time, this is the setting you want. Below are the steps, which time to pick, and what to do when the option will not change.
The fix
Change the screen lock time
- 1
Open Settings and tap Display & Brightness.
- 2
Tap Auto-Lock.
- 3
Choose a time.
Your iPhone offers 30 Seconds, 1 Minute, 2 Minutes, 3 Minutes, 4 Minutes, 5 Minutes and Never.
- 4
Check it worked.
Leave the iPhone untouched. The screen should dim and then lock after the time you chose.
Which Auto-Lock time should you choose?
- 30 Seconds or 1 Minute: best for battery and privacy. The screen turns off quickly when you put the iPhone down.
- 2 to 3 Minutes: a good middle choice if the screen locks before you finish reading a long message or a recipe.
- 4 to 5 Minutes: useful when you follow directions or keep a page open, but the screen is the biggest battery drain on an iPhone.
- Never: the screen stays on until you press the side button. Use it for a short job, then switch it back.
If the screen uses power and your battery drops fast, a shorter time helps. Our guide to an iPhone battery that drains fast covers other causes.
Auto-Lock is greyed out or stuck at 30 seconds
This is the most common problem. Low Power Mode sets Auto-Lock to 30 seconds to save battery, and while it is on you cannot pick a longer time. The setting looks greyed out or goes back to 30 seconds. Fix it like this:
- 1
Open Settings › Battery.
- 2
Turn off Low Power Mode.
The yellow battery icon in the status bar goes away when it is off.
- 3
Go back to Settings › Display & Brightness › Auto-Lock.
The options are available again. Pick your time.
Low Power Mode can switch itself back on when the battery gets low. If your Auto-Lock keeps returning to 30 seconds, check whether Low Power Mode turned on again. See what Low Power Mode does for what else it changes.
Auto-Lock still greyed out with Low Power Mode off?
- A work or school profile can set a maximum Auto-Lock time or lock the setting. Look in Settings › General › VPN & Device Management. If a profile is listed, ask the person who manages it.
- Restart the iPhone and open the setting again. A quick restart clears a stuck settings screen.
- Update iOS in Settings › General › Software Update, in case a bug is stopping the setting from saving.
The screen dims or locks sooner than the time you set
Auto-Lock is not the only thing that dims the display. If the screen darkens early, check these:
- Attention Aware Features. On Face ID iPhones, Settings › Face ID & Passcode has this switch. When it is on, the iPhone can dim the screen before it locks if you are not looking at it.
- Auto-Brightness. It lowers brightness in dim rooms, which can look like the screen is shutting off. See auto brightness that is not working.
- Heat. A very hot iPhone dims its screen to protect itself.
Why the screen stays on when Auto-Lock is set
Some apps keep the screen awake on purpose, such as video players, maps with navigation and some games. The iPhone does not lock while they run. If the screen never turns off and Auto-Lock is not set to Never, close those apps and try again.
Auto-Lock is not the same as Require Passcode
Two settings work together. Auto-Lock turns the screen off. Require Passcode in Settings › Face ID & Passcode sets how soon you must unlock after the screen turns off. With Immediately, you always need Face ID or your passcode. For privacy, keep Auto-Lock short and Require Passcode on Immediately.
Other display settings
Brightness, text size, Always On Display and wallpaper all live near Auto-Lock. Our guide to all iPhone display settings shows where each one is.
Frequently asked questions
Where is screen lock time on iPhone?
Open Settings › Display & Brightness › Auto-Lock. Apple calls the screen lock time Auto-Lock. Pick 30 Seconds, 1 to 5 Minutes, or Never.
Why can’t I change the screen lock time on my iPhone?
Low Power Mode is the usual cause. It locks Auto-Lock at 30 seconds and greys it out. Turn Low Power Mode off in Settings › Battery, then change Auto-Lock. A work or school profile can also restrict it.
What is the longest screen lock time on an iPhone?
5 minutes, or Never. The Never option keeps the screen on until you press the side button, which uses more battery.
Is Auto-Lock the same as the passcode delay?
No. Auto-Lock turns the screen off. Require Passcode, in Settings › Face ID & Passcode, controls how soon after that you must unlock with a passcode or Face ID.
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