How to fix an Apple iPhone that keeps restarting [Troubleshooting Guide]

High-end devices like your Apple iPhone that keeps restarting may have some issues with its firmware. It could also be a sign of a hardware issue but there’s only so much you can do about it if that’s really the case. What you can do is rule out the possibility that it’s just a firmware problem and if your phone still continues to restart after your troubleshooting, then that’s the time you can set an appointment at the Genius Bar so that an Apple technician can check the device for you.

Random restarts and other performance issues are common symptoms of memory problems like when the phone is running low on storage. Usually, your phone will prompt you with a warning message, telling you that the internal memory is too low and that you need to free up space. Nonetheless, there are also some cases where the phone would just crash and then restarts on its own without giving any sort of warning. If the hardware isn’t to blame, then performing some tweaks will likely save your device. Read on to learn what to do if your iPhone keeps restarting on its own.

Before we proceed, if you’re looking for a solution to a problem with your phone, try to browse through our troubleshooting pages to see if we support your device. If your phone is in the list of our supported devices, then go to the troubleshooting page and look for similar problems. Feel free to use our solutions and workarounds. Don’t worry it’s free. But if you still need our help, then fill up our iPhone issues questionnaire and hit submit to contact us.

First solution: Forced restart.

The simplest solution to random restarts attributed to minor firmware crashes is a forced restart. It’s an alternative to a soft reset on the iPhone. Like a soft reset, it clears out junk files from the phone’s internal memory including corrupt files that caused the system to crash. And similar to a soft reset, performing a forced restart on your iPhone doesn’t affect any saved information hence, it won’t result to permanent data loss. There are different ways to force restart an iPhone, depending on the device model.

If you’re using an iPhone 7 or iPhone 7 Plus, follow these steps to force restart:

  • Press and hold the Volume Down button and the Power (Sleep/Wake) button simultaneously and then release both buttons with the Apple logo appears.

If you’re using an iPhone 6s, 6s Plus and earlier variants, a forced restart is done this way:

  • Press and hold both the Power (Sleep/Wake) button and the Home button for a few seconds and then release both buttons when the Apple logo is displayed on the screen.

If you’re using an iPhone 8, 8 Plus and later iPhones, here’s how a forced restart is carried out:

  1. Press and release the Volume Up button.
  2. Then press and release the Volume Down button.
  3. Finally, press and hold the Side button and then release it when the Apple logo appears.

Once the phone has rebooted, eliminate all possible triggers by performing the next procedures.

Second solution: Uninstall bad apps to fix iPhone that keeps restarting.

Rogue apps are usually the main culprits. If your iPhone started to act up after installing or updating an app, then that app is likely the trigger. In that case, deleting the suspected app from your iPhone is recommended. Just refer to these steps:

  1. Tap Settings from your Home screen.
  2. Tap General.
  3. Select iPhone Storage.
  4. Navigate to the bottom of the screen then find the suspected app.
  5. Tap to select the app that you want to delete then tap Delete App.
  6. Finally, tap Delete to confirm that you want to delete the selected application.

After deleting the suspected app, restart/soft reset your iPhone then use it as you normally do to test and see if the problem is gone. If your iPhone still keeps restarting after this, consider the next options.

Third solution: Install pending updates for apps and iOS.

Updates are not only pushed to bring in new features but also offer fix patches to get rid of bug-inflicted symptoms on the phone. If you haven’t configured your apps and device to auto-update, then you will need to manually install updates. Your phone must have stable Internet connection, sufficient storage space, and battery life to complete the updating process.

To check for pending app updates, just follow these steps:

  1. From the Home screen, tap App Store to launch the Apple Store application.
  2. Then navigate to the bottom of the screen and tap Updates. A list of apps with pending updates will then show up.
  3. To update individual apps, tap the Update button next to the name of the app.
  4. Or tap the Update All button to install all app updates at once.

Aside from app updates, also care to check for new iOS version available. Just follow these steps to check for new iOS update on your iPhone:

  1. Tap Settings from your Home screen.
  2. Select General.
  3. Tap Software Update.

If an update is available, you will see a notification containing the update details, bug fixes, and system requirements. Read and review the information then follow the onscreen prompts to download and install the update on your phone.

After installing new updates, reboot/soft reset your iPhone to save and apply the recent system changes and likewise to refresh the apps and system services. If your iPhone still keeps restarting, the next solution might help you.

Fourth solution: Reset all settings.

You may have to consider performing some settings reset to eliminate invalid settings or erratic customization on your device. This reset is also recommended to fix an iPhone that’s suddenly acting up following an iOS update installation. Unlike a factory reset, this reset does not affect any saved information on the phone. Hence, backing up files won’t be necessary. Here’s how it works:

  1. From the Home screen, tap on Settings.
  2. Tap General.
  3. Scroll down to and tap on Reset.
  4. Choose the option to Reset all settings.
  5. Enter your device passcode when asked to continue.
  6. Confirm that you want to reset all settings on your iPhone.

The phone will restart automatically when the reset is finished and then loads the original options and values. To use features that are disabled by default, you will need to re-enable them first. That said, enable Wi-Fi on your iPhone first-hand so that you’ll be able to use online apps and services. Test your iPhone and observe closely to know if it still keeps restarting after this procedure because if it does, then try the next solutions.

Fifth solution: Reinstall the SIM card on your iPhone.

If an iPhone keeps restarting on its own, the problem can also be tied to SIM card issues. I’ve experienced this same problem with my old iPhone 5 before after I removed its SIM card. It turned out the phone crashes and reboots on its own as it couldn’t get to detect any SIM card in it. Thus, reinstalling the SIM card on your iPhone may also be the key to fixing this problem. Here’s what you should do then:

  1. Start by turning your iPhone off.
  2. While your phone is turned off, insert the SIM card ejector tool into the tiny hole on the SIM card tray located on the side of your phone.
  3. Gently push the ejector tool until the tray pops out.
  4. Remove the tray from the phone.
  5. Then take the SIM card out from the tray. Check and ensure no signs of damage (liquid traces or scratches) to the tray or SIM card itself.
  6. If everything looks good, place the SIM back into the tray in the same orientation before you removed it.
  7. Secure the SIM card in place then push the SIM tray back into the phone.

Turn on your iPhone and use it to test whether or not the symptom is gone. It it recurs, then you are most likely dealing with some fatal system error on your iPhone, which requires more advanced solutions.

Sixth solution: Erase your iPhone (factory reset).

The problem is most likely inflicted by some stubborn system bugs as it managed to withstand the prior methods. In this case, your next option would be to erase your iPhone and restore its factory defaults. But given that your iPhone is randomly restarting, it would be better to carry out a factory reset through iTunes. This then requires you to secure a Windows or Mac computer with the latest version of iTunes software installed. Once you’re all set, proceed with these steps to start erasing your iPhone in iTunes.

  1. Launch iTunes on your computer.
  2. Connect your iPhone to the computer using the Apple-supplied cable or Lightning cable that came with it.
  3. If prompted to enter your device passcode or Trust This Computer, simply follow the onscreen instructions to proceed.
  4. Select your iPhone when it shows up in iTunes.
  5. Navigate to the Summary section, then click the button to Restore [iPhone]. You may also opt to back up files from your iPhone before restoring it. Just click the Back Up iPhone button to do so.
  6. Finally, if prompted with a warning message, click the Restore button to confirm.

Wait for iTunes to finish erasing your device. When the reset is finished, factory settings are restored and your iPhone restarts. By then, you can proceed with the initial setup process and set up your iPhone as new. Continue using your phone to know if it still keeps restarting on its own because if it does, you have to restore it in iTunes.

Last resort: Restore your iPhone in iTunes.

If the problem isn’t remedied by a factory reset, then this is when you consider carrying out iOS restore. There are two types of system restore you can do in this case. You can try performing a recovery mode first and if that doesn’t help, proceed with the DFU mode restore. Once again, you’re going to use iTunes on a Mac or Windows computer to perform these restore methods. To get started, connect your iPhone to the computer with the original USB cable or Lightning cable. Once the phone is connected, you can refer to these subsequent methods to access recovery mode.

To enter recovery mode in iPhone 8 or later models, refer to these steps:

  1. Press and quickly release the Volume Up button.
  2. Then press and quickly release the Volume Down button.
  3. Finally, press and hold the Side button until the Recovery Mode screen appears.

To enter recovery mode on iPhone 7 and iPhone 7 Plus, follow these steps:

  • Press and hold the Side/Power button and Volume Down button simultaneously and then release both buttons when the Recovery Mode screen shows up.

To enter recovery mode on iPhone 6s, 6s Plus, and earlier models, here’s what you should do:

  • Press and hold both the Home button and Top/Power buttons simultaneously and then release both buttons when the Recovery Mode screen appears.

Don’t release the last button if you see the Apple logo because you need to enter recovery mode. The recovery mode interface is depicted by the Connect to iTunes screen.

If recovery mode restore failed to fix your iPhone…

As mentioned earlier, you may have to consider restoring your iPhone in DFU mode if the problem continues after a recovery mode restore. DFU or Device Firmware Update mode is deemed as the deepest type of system restore done on an iPhone. It puts your device in a state that allows it to communicate with iTunes on a computer even without activating the bootloader. This is usually necessary to repair an iPhone with a corrupt operating system. There are different ways to enter recovery mode and the steps would vary depending on the device model.

To enter DFU mode on the iPhone 6s, SE and earlier models, follow these steps:

  1. Connect your iPhone to the computer using the Apple-supplied USB cable/Lightning cable.
  2. When it’s connected, hold down both the Home button and Sleep/Wake button for about 8 seconds.
  3. After the elapse time, release the Sleep/Wake button but keep holding down the Home button until the screen is completely black.

If you see the Apple logo, it means that you’ve held down the Sleep/Wake button for too long and so you’ll have to start all over from the very beginning.

To enter DFU mode on the iPhone 7 and 7 Plus, follow these steps:

  1. Connect your iPhone to the computer via USB cable.
  2. While the device is connected, hold down both the Side button and Volume Down button simultaneously for 8 seconds.
  3. After the elapsed time, release the Side button but keep holding down the Volume Down button.

Holding the Side button for too long will prompt you with the Apple logo instead of a black display. If that happens, then you will need to start all over. But if the screen remains black, it denotes that your iPhone has successfully entered DFU mode and is all set for iTunes restore.

To enter DFU mode on the iPhone 8, 8 Plus, X and later models, refer to these steps:

  1. Connect the phone to the computer using the supplied USB cable.
  2. While the device is connected, press and release the Volume Up button.
  3. Then quick-press and release the Volume Down button.
  4. Press and hold down the Side button until the screen turns black then hold down both the Side button and Volume Down button for 5 seconds.
  5. After 5 seconds, release the Side button but keep holding down the Volume Down button until nothing is displayed on the screen.

After successfully entering DFU mode, you can continue to restore your iPhone through iTunes. Just be sure not not disconnect your device from the computer during the restore process to avoid ruining the operating system and end up having a bricked iPhone instead.

iPhone still keeps restarting?

If your iPhone still keeps restarting after exhausting all prior methods, then you’ll have to rule out hardware-related issues next. Your phone might have obtained some hardware damage from previous incidents of dropping or liquid exposure. If that’s the case, repair/service is needed. You can take your device to the nearest Apple service center and ask an iPhone technician to scrutinize the hardware components and if necessary, fix whatever part that’s damaged.

I hope that we’ve been able to help you fix your iPhone that keeps restarting on its own one way or another. We would appreciate it if you helped us spread the word so please share this post if you found it helpful. Thank you so much for reading!