These days we expect reliability from our iPhones and other Apple devices, and most of the time they are highly dependable, so when your iPhone restarts unexpectedly it may be very worrying. If you’ve been asking yourself, “Why does my iPhone keep restarting?” we’ll show you a handful of fixes and troubleshooting steps for this unusual but concerning problem.
Answer This First
Here’s the first question: Do your phone restarts happen at unpredictable, seemingly random times, and work fine in between these spontaneous restarts? If so, please start at the beginning of our guide by backing up your phone and then attempting possible solutions and troubleshooting. If, however, your phone is stuck in a loop of continuously restarting, backing up your phone, and most of the other recommended steps will not be possible, so skip directly to attempting a Force Restart to try to break the loop. For more helpful guides on your Apple devices, make sure to sign up for our free Tip of the Day newsletter.
What’s in this Guide?
- Back Up Your iPhone
- Consider the Possible Causes
- Update System Software
- Update All Apps
- Check Analytics Data
- Force Restart Your iPhone
- Remove and Reinsert SIM Card
- Reset Your iPhone’s Settings
- Restore Your iPhone to Factory Defaults
Back Up Your iPhone
When troubleshooting a serious issue, it’s a good idea to back your phone up to a computer so that if anything goes wrong your data will be preserved. Before moving forward with other steps, check out our article on how to back up to iCloud, our guide on backing up to a Mac, or our guide on backing up to a Windows PC with iTunes.
Consider the Possible Causes
There are several possible causes of an iPhone restarting intermittently or getting stuck in a restart loop, so the first step is to think about whether any of these stand out as the most likely culprit.
- Did you recently install a new app, or make a big change to system settings? If so, try uninstalling the app, or reversing the setting change. These issues may be caused by a software problem so if the problem began only after making a change like this, it may be the cause.
- Does the restarting only occur while charging the phone? Check the lightning port and cable to make sure they are clean and undamaged.
- Did your phone suffer a drop or other physical damage? If so, it may be a hardware problem such as damage to the SIM card. Try reinserting the SIM card or testing the phone without it.
Update System Software
It’s almost always a good idea to keep your iOS system software up to date, and this is especially true when you’re experiencing glitches as your issue may be fixed by a recent update. Take a look at our guide on updating iOS if you need more help.
Update All Apps
Similarly, make sure all your downloaded apps are up to date, in case a bug with one of them may be at the heart of the issue. Check out our guide on updating all your apps at once for more details.
Check Analytics Data
Did you know your iPhone creates regular logs of analytics data and errors? These logs are difficult to understand by those of us who aren’t tech professionals, but they can still give valuable clues. We recommend doing a quick scan of the most recent few logs, and if you see the same app mentioned repeatedly, it may be causing the issue. Try uninstalling any apps you see mentioned more than once in recent logs and waiting to see if this solves the problem. Here’s how to find the logs.
- Open Settings.
- Find and tap Privacy.
- Tap Analytics & Improvements.
- Tap Analytics Data.
- Tap a recent log to open it.
Force Restart Your iPhone
Performing a Force Restart is not something you want to do often, but it can hep to get your device out of error loops and purge data from memory that might be causing glitches. See our guide on how to force restart an iPhone X or later, or this guide on how to do so on earlier iPhones with Home buttons.
Remove & Reinsert Your SIM Card
Image courtesy of Apple
If you think the cause could be a physical problem with the phone, one thing to try is removing the SIM card. Check our guide on how to remove and reinsert your SIM card. Try using your iPhone without the SIM card for a while, and if the issue stops while the SIM card is removed but starts again once the card is replaced, you will likely need to contact your cell carrier to replace the card. If you have access to a second SIM card, or if you have access to a second iPhone, you can try using the first SIM card in a second phone, to try to narrow the issue down to either the iPhone or the SIM card.
Reset Your iPhone’s Settings
A good step to try at this point is to try resetting some of your phone’s settings. Check out our guide on how to reset your network settings, which we recommend starting with as this is both a fairly likely cause of the problem, and a less severe reset. If that doesn’t help resolve the issue, you can try the Reset All Settings option, which can be found in the same menu. In both cases, you’ll keep all data and apps, but many personalized settings will be lost and will need to be reentered or configured again.
Restore Your iPhone to Factory Defaults
The final option is by far the most drastic, so consider things very carefully before you attempt it. If none of the previous steps have helped, you may do a full factory reset of your iPhone. This will wipe all data from your phone and revert all settings to their original defaults, after which you will need to restore your iPhone from the backup you made earlier. Before you restore from your backup, however, be sure to test your iPhone to see if the random restart issue is still occurring. If it is, this is very likely to be a hardware problem that will require help from Apple technicians.
Even before doing the factory restart, you may want to contact Apple Support. Through the official support site, you can communicate with an Apple associate via phone, chat, or email. If you decide you need to fully reset your phone, however our article on the iPhone reset process will explain the things you should consider beforehand and walk you through the steps when you’re ready.
Hopefully, by now you have resolved the issue or learned enough to identify the root of the problem, and the next time you find yourself asking, “Why did my phone randomly restart?” you’ll know what to do!
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