To change how long your iPhone waits before the screen locks, go to Settings > Display & Brightness > Auto-Lock and pick a time from 30 seconds to 5 minutes, or Never. The new time applies right away, on every iPhone model, including on iOS 26 and iOS 27.
If Auto-Lock is grayed out and stuck at 30 seconds, Low Power Mode is on. Turn it off and you can choose a longer time again. If you meant changing the look of your Lock Screen, such as the wallpaper or clock style, skip to that section.
How to change the screen lock time (Auto-Lock)
- Open Settings.
- Tap Display & Brightness.
- Scroll down and tap Auto-Lock. The row shows your current time.
- Tap the time you want. A check mark appears next to it.
There’s no save button. Go back or close Settings, and the screen now waits that long after your last touch before it dims and locks. For most people, 1 or 2 minutes is a good balance between battery life and not having the screen go dark while reading.
Note: iOS 27 moved text and zoom options into a new Appearance menu, but Auto-Lock is still in Display & Brightness.
Which “lock time” setting do you need?
Three different settings affect when your iPhone locks or goes dark. Here’s how they differ:
| Setting | What it controls | Where to find it |
|---|---|---|
| Auto-Lock | How long the screen stays on when you’re not touching it | Settings > Display & Brightness |
| Require Passcode | How soon after locking the passcode is needed again | Settings > Face ID (or Touch ID) & Passcode; locked to Immediately if you use Face ID, Touch ID or Apple Pay |
| Always On Display | Whether a dimmed Lock Screen stays visible after the phone locks | Settings > Display & Brightness (supported models only) |
Choosing Never
Never keeps the screen on until you press the side button. It’s handy for a recipe or a presentation, but it drains the battery and leaves your phone unlocked if you set it down and walk away. Our guide to turning off Auto-Lock covers when Never makes sense and how to switch back safely.
Why is Auto-Lock grayed out?
Apple lists “Sets Auto-Lock to 30 seconds” as one of the things Low Power Mode does. While it’s on, the Auto-Lock row is locked and you can’t pick another time. Low Power Mode is on when the battery icon in the status bar is yellow.
To turn it off on iPhone 15 or later:
- Open Settings > Battery.
- Tap Power Mode.
- Turn off Low Power Mode.
On iPhone 14 and earlier, go to Settings > Battery and turn off the Low Power Mode switch. You can also tap the battery button in Control Center if you’ve added it. Low Power Mode also turns itself off once the battery charges to 80%.
If Low Power Mode is off and you still can’t pick a longer time, your iPhone may be managed by a school or employer. Their device profile can limit the Auto-Lock choices, and only the organization can change that.
Why does the screen dim sooner or later than the time I set?
On iPhones with Face ID, Attention Aware Features check if you’re looking at the screen. If you are, the iPhone won’t dim it; if you look away, it may dim a bit early. You’ll find the switch in Settings > Face ID & Passcode.
Some apps, such as video players and navigation apps, keep the screen on while they’re in use no matter what Auto-Lock says.
On the iPhone 14 Pro, 14 Pro Max, 15 Pro, 15 Pro Max, 16 Pro, 16 Pro Max, iPhone 17, 17 Pro and 17 Pro Max, Always On Display keeps a dimmed version of the Lock Screen visible after Auto-Lock kicks in. The phone is still locked. Turn it off in Settings > Display & Brightness > Always On Display if you’d rather the screen go fully black.
How to change how soon the passcode is required
By default, your iPhone asks for the passcode as soon as the screen locks. If you use Face ID, Touch ID or Apple Pay, you can’t change that. Apple keeps it at Immediately for security.
On an iPhone without those features turned on, open Settings > Touch ID & Passcode (or Passcode), enter your passcode, and tap Require Passcode to choose a delay. A delay means anyone who picks up your phone shortly after it locks can open it, so keep it short. Apple explains the rules in its iPhone passcode guide.
How to change what your Lock Screen looks like
If you searched for “change lock screen” and meant the wallpaper, clock or widgets, that’s a different setting from Auto-Lock. On iOS 16 and later:
- Unlock your iPhone with Face ID or Touch ID, but stay on the Lock Screen.
- Touch and hold the Lock Screen until Customize appears at the bottom.
- Tap Customize, then tap Lock Screen.
- Tap the clock to change its font and color, tap the areas above or below it to add widgets, or change the photo.
- Tap Done.
To start from a new design instead, swipe to the end of the Lock Screen gallery and tap the + button. For full walkthroughs, see how to set up a new Lock Screen and how to change the color of the clock on your Lock Screen.
The time shown on the Lock Screen follows your iPhone’s clock. If it’s wrong, fix it in Settings > General > Date & Time, where Set Automatically should normally be on.
How to lock your iPhone right now
Press the side button once (on very old models with a Home button, the button is on top). The screen turns off and locks immediately, whatever your Auto-Lock time is. This is the quickest habit if you pick a long Auto-Lock time.
Matthew Roberts is the founder and editor of ARS Digitech. He started the site to answer the iPhone questions his friends and family kept asking him, and it has grown into a library of iPhone and iOS how-to guides. Matthew writes and maintains every tutorial on the site, checking steps and menu names against Apple’s official support documentation and updating guides when an iOS release moves a setting.