Some people say their iPhone randomly restarted overnight or even shut down at night without turning back on before the morning alarm is about to go off.
Waking up to the passcode screen is the best indication that your iPhone had experienced a restart while you were asleep. Apple’s security policy requires entering the passcode after restarting the device before using Face ID or Touch ID again.
For security, turning an iPhone off and back on disables other features until the passcode is entered. For some folks, this interrupted their morning alarms as their phone wouldn’t turn on automatically after shutting down at night.
Some iPhones restarting or shutting down overnight
This problem is well documented in online forums like Reddit, with 9to5Mac and MacRumors confirming that some of their staff are suffering from the same problem. Apple didn’t release a statement at post time.
You can verify whether this has happened on your device by checking Settings > Battery to see if there’s a gap in battery stats during the night.
Various iPhone models are affected, including the iPhone 13, iPhone 14 and iPhone 15 lineups. For some folks, their device would restart if left on a charger overnight. Others say it only happens sporadically rather than every night. Some phones restart if left on a MagSafe charger at night, but others still restart even if not charging at all.
It’s unclear how widespread this issue is. It’s easy to chalk it up to iOS 17, but it seems the problem has been a regular occurrence for some people since the iPhone X. On Apple’s forums, for example, you can find threads dating back a few years about iPhones occasionally shutting down while charging overnight.