When your iPhone 16 Pro starts restarting on its own, it's incredibly disruptive. This can happen for a few reasons, often tied to a new software update or a problematic app you've recently installed. I'd start with a force restart, as it's the quickest way to clear out a temporary software hiccup.
Before you try anything more involved, it's a good idea to make sure you have a recent backup. You can do this through iCloud or by connecting to your computer. This protects your photos, messages, and app data just in case.
Perform a Force Restart
The force restart sequence for the iPhone 16 Pro is the same as recent models. Press and quickly release the Volume Up button, then quickly press and release the Volume Down button. Immediately after, press and hold the Side button. Keep holding it until you see the Apple logo appear, then you can let go.
This doesn't erase any data. It simply forces the phone to shut down and reboot, which can resolve many minor glitches causing the random restarts.
Update iOS and Your Apps
Since you're running iOS 26, there's a chance a bug in the current version is causing instability. Head to Settings > General > Software Update to check for any available updates. Installing the latest iOS version often includes critical bug fixes.
Outdated apps can also be the culprit. Open the App Store, tap your profile icon in the top corner, and scroll down to see pending updates. Tap "Update All" to get everything current. This ensures all your software is playing nicely together.
Identify a Problematic App
If the restarts started after you installed a new app, that app might be the issue. Try closing all your open apps first. On the iPhone 16 Pro, you swipe up from the very bottom of the screen and hold in the middle, then swipe up on each app card to close it.
If the problem seems random, you can check your analytics logs for clues. Go to Settings > Privacy & Security > Analytics & Improvements > Analytics Data. Look for log entries that start with the name of an app you use often, followed by the word "crash." Finding a specific app here repeatedly can point you to the offender.
Free Up Storage Space on Your iPhone
When your iPhone's storage is critically full, the system can become unstable. Go to Settings > General > iPhone Storage to see how much space you have left. If you're in the red, the phone itself will offer recommendations like reviewing large attachments or offloading unused apps.
Offloading an app removes the app itself but keeps its documents and data on your phone. You can always re-download it from the App Store later if you need it. This is a great way to quickly free up gigabytes without losing your information.
Reset All Settings
This is a more thorough step that won't delete your personal data like photos or messages. It resets all your system settings back to their defaults. Things like your Wi-Fi passwords, wallpaper, and privacy permissions will be cleared, so you'll need to set those up again.
To do this, go to Settings > General > Transfer or Reset iPhone > Reset. Then, choose "Reset All Settings." You'll need to enter your passcode to confirm. This can resolve conflicts caused by a corrupted settings file.
Check for Overheating Issues
The iPhone 16 Pro is a powerful device, and intensive tasks can cause it to heat up. If the phone gets too hot, it will protect its components by shutting down or restarting. Think about when the restarts happen. Is it during long gaming sessions, while using GPS navigation, or when charging?
If overheating is the trigger, remove any case to help with cooling and move the phone out of direct sunlight. Also, make sure you're using a certified USB-C cable and charger. An uncertified charger can cause irregular power delivery, which might lead to both overheating and system instability.
Restore via Recovery Mode
If your phone is stuck in a continuous restart loop, you'll need to use recovery mode. First, connect your iPhone 16 Pro to a Mac or PC with a cable. On a Mac with macOS Catalina or later, open Finder. On a PC or older Mac, open iTunes.
Quickly press and release the Volume Up button, then quickly press and release the Volume Down button. Immediately press and hold the Side button. Don't let go when you see the Apple logo. Keep holding until you see the recovery mode screen (a cable pointing to a computer icon).
Your computer will then give you the option to Update or Restore. Choose "Update" first. This will try to reinstall iOS without erasing your data. If the update fails, you'll need to choose "Restore," which will install a fresh copy of iOS and erase your phone, so you'd need a backup to recover from.
Inspect the SIM Card
A faulty or loose SIM card can sometimes cause system instability. Locate the SIM tray on your iPhone 16 Pro and use the SIM eject tool (or a paperclip) to pop it out. Carefully remove the SIM card and check the gold contacts for any visible dirt or damage.
Gently wipe the contacts with a soft, dry cloth and then reinsert the SIM card, making sure it's seated properly in the tray. Push the tray back into the phone until it clicks. This is a simple physical check that can rule out one potential hardware-related cause.
Perform a Factory Reset
This is your last resort before considering a hardware issue. A factory reset will erase everything on your iPhone 16 Pro and install a clean version of iOS. You must have a backup to restore from afterward.
Go to Settings > General > Transfer or Reset iPhone and tap "Erase All Content and Settings." Enter your passcode and Apple ID password to confirm. If the random restarts stop on a completely clean phone, it strongly points to a software or app problem that's now been removed.
