Having your phone shut down and reboot unexpectedly is one of the most frustrating issues an iPhone owner can face. Learning how to fix an iPhone that keeps restarting on its own can save you from data loss, missed calls, and the headache of an unreliable device. Whether your phone reboots every few minutes or randomly throughout the day, the underlying cause is usually traceable with the right approach.
The good news is that most restart loop problems come from software issues that you can fix yourself at home. Software glitches, corrupted updates, and problematic apps account for the majority of cases. Hardware failures like a worn-out battery or damaged charge port are the next most common culprits, and even those are relatively affordable to address.
In this guide, our team walks you through every troubleshooting step in order, starting with the simplest fixes and progressing to more advanced methods. We cover force restart instructions for all iPhone models, how to check your battery health, when to use Recovery Mode or DFU Mode, and how to read kernel panic logs. By the end, you will know exactly what is causing your iPhone to keep restarting and how to fix it.
Why Your iPhone Keeps Restarting on Its Own
Your iPhone keeps restarting on its own because something is triggering a system-level error that the operating system cannot recover from. The phone reboots as a protective measure, attempting to clear the error and start fresh. Understanding whether you are dealing with a software or hardware problem is the first step toward fixing it.
Software Causes (Most Common)
Software issues are the leading reason an iPhone enters a restart loop. These are generally fixable without professional help.
Failed or incomplete iOS updates top the list. If an update gets interrupted by a lost connection or low battery, the partially installed firmware can cause continuous crashes. We have seen this happen frequently after major iOS releases, especially on older devices.
Problematic apps are another major trigger. An app with a bug or compatibility issue can crash the entire system, forcing a restart. If your iPhone started rebooting right after you installed a new app, that app is the likely suspect. Social media apps, poorly optimized games, and apps from small developers are the most frequent offenders.
Insufficient storage can also cause random restarts. When your iPhone has less than 1 GB of free space, the system struggles to manage temporary files and background processes. This pressure can trigger crashes that look exactly like a hardware failure.
Corrupted system files from malware, failed jailbreaks, or simply aging software can destabilize iOS. While iOS is generally secure, a corrupted system file from a bad update download can cause the iPhone to crash repeatedly.
Hardware Causes (Less Common but More Serious)
Hardware problems account for a significant share of persistent restart loops. These issues will not resolve with software fixes and typically require component replacement.
A degraded battery is the single most common hardware cause. When battery health drops below 80%, the battery can no longer deliver consistent voltage during peak power draws. The phone detects this as a system error and restarts to protect itself. Users on Reddit frequently report that their iPhone kept restarting until they replaced a battery that was at 75% health or lower.
A faulty charge port can cause intermittent power delivery issues that confuse the power management system. If your iPhone only restarts while plugged in, the charge port is a prime suspect.
Damaged sensors or logic board components can trigger what Apple calls a “kernel panic.” The system detects missing or erratic sensor data and restarts as a safety measure. This often shows up in diagnostic logs as a “thermalmonitord” or “watchdog timeout” entry.
Liquid damage, even minor exposure, can corrode connectors on the logic board over time. This corrosion disrupts signals between components and causes random reboots that worsen gradually.
Here is a quick comparison to help you identify which type of issue you are facing:
Signs of a software problem: restarts started after an update, app install, or settings change. Phone works normally between restarts. Force restart provides temporary relief.
Signs of a hardware problem: restarts happen at specific battery levels (especially below 20-30%), phone gets unusually hot, or restarts persist even after a complete factory reset. Battery health reads below 80%.
How to Fix an iPhone That Keeps Restarting: Force Restart First
The first fix you should always try is a force restart. This is different from a normal restart because it cuts power to the system entirely and forces a fresh boot. A force restart clears temporary memory, stops crashed processes, and often resolves one-time software glitches that cause continuous rebooting. It will not erase any of your data, photos, or apps.
The button combination for a force restart depends on your iPhone model. Use the correct instructions below for your device.
Force Restart iPhone 8, X, XS, XR, 11, 12, 13, 14, 15, 16, and SE (2nd Gen and Later)
Press and quickly release the Volume Up button. Then press and quickly release the Volume Down button. Finally, press and hold the Side button (the power button on the right side) until you see the Apple logo appear on screen.
Keep holding the Side button even after the screen goes black. The Apple logo should appear within 10-15 seconds. Once it does, release the button and let the phone boot up normally.
Force Restart iPhone 7 and 7 Plus
Press and hold both the Volume Down button and the Sleep/Wake button (the power button on the right side) at the same time. Keep holding both buttons until the Apple logo appears on the screen, then release them.
This model uses a different combination than newer iPhones because the home button is not a physical button. Make sure you press both buttons simultaneously for the force restart to work correctly.
Force Restart iPhone 6s, 6s Plus, SE (1st Gen), and Earlier
Press and hold both the Home button (the circular button below the screen) and the Sleep/Wake button (the power button on the top or right side) at the same time. Keep holding both until the Apple logo appears, then release them.
This method works for all iPhone models with a physical Home button. If your Home button is broken, you can enable AssistiveTouch in Settings, create a custom gesture, or connect a external keyboard to trigger a restart.
What If the Force Restart Does Not Help?
If your iPhone keeps restarting even after a force restart, do not worry. A force restart only fixes temporary glitches. The remaining steps in this guide address deeper software and hardware issues. Move on to the software troubleshooting section next.
One important note: if your iPhone is stuck in a continuous restart loop and you cannot keep it running long enough to change any settings, connect it to a computer with a USB cable. This gives you access to Recovery Mode and Finder or iTunes restore options, which we cover later in this guide.
Software Troubleshooting Steps
If a force restart did not solve the problem, the next step is software troubleshooting. These methods address corrupted updates, problematic apps, and system file errors. Work through them in order, testing after each step to see if the restarts stop.
Step 1: Install Any Available iOS Updates
Apple regularly releases iOS updates that fix known bugs causing crashes and restarts. Installing the latest version of iOS is one of the most effective fixes for an iPhone that keeps restarting, especially if the problem started after a major update.
To update via Settings, open the Settings app and tap General, then tap Software Update. If an update is available, tap Download and Install. Make sure your iPhone is connected to Wi-Fi and has at least 50% battery or is plugged into a charger before starting.
If your iPhone restarts too quickly to complete the download, you will need to update using a computer instead. Connect your iPhone to a Mac or PC, open Finder (on macOS Catalina or later) or iTunes (on older macOS or Windows), select your device, and click Check for Update. This method is more stable because the computer handles the download and installation.
Step 2: Update via Recovery Mode (When Stuck in a Loop)
If your iPhone will not stay running long enough for a normal update, Recovery Mode lets you reinstall iOS from a computer. This method does not erase your personal data if you choose Update instead of Restore.
Connect your iPhone to a computer with a USB cable. Open Finder or iTunes. Then perform the force restart button combination for your model, but keep holding the buttons until you see a Recovery Mode screen with a computer icon and a USB cable (instead of the Apple logo).
Finder or iTunes will detect your iPhone in Recovery Mode and display a prompt with two options: Update or Restore. Always click Update first. This attempts to reinstall iOS without erasing your data. If Update fails, you will need to click Restore, which does erase everything.
Step 3: Identify and Remove Problematic Apps
A buggy or incompatible app can crash iOS and force a restart. The trick is identifying which app is responsible. Apple provides a built-in diagnostic tool for this.
Go to Settings, then Privacy and Security, then Analytics and Improvements, and tap Analytics Data. This shows a long list of log files. Scroll through and look for entries that start with the name of any app you recently installed or updated, especially entries containing “panic” or “crash.”
If you find repeated crash logs from a specific app, that app is likely causing your restart issue. Delete it by pressing and holding the app icon, tapping Remove App, then Delete App. Restart your iPhone and monitor for 24 hours.
Another approach: think about what changed recently. Did the restarts start after you installed a new app, updated an existing app, or changed a setting? If so, undo that change and see if the problem resolves.
Step 4: Free Up Storage Space
iOS needs adequate free space to manage temporary files, swap data, and run background processes. When storage drops below 1 GB, the system can become unstable and trigger random restarts.
Check your available storage by going to Settings, then General, then iPhone Storage. This screen shows how much space each app uses and provides recommendations for freeing up space.
Aim for at least 5 GB of free storage for optimal system performance. Delete unused apps, remove old videos and photos, clear Safari history and website data, and offload large message attachments. You can also enable Offload Unused Apps to automatically remove apps you rarely use while keeping their data.
Step 5: Reset All Settings
If none of the above steps worked, a settings reset can fix corrupted configuration files that cause crashes. This option resets all system settings (Wi-Fi passwords, Bluetooth pairings, wallpaper, privacy settings, etc.) to their defaults without erasing your apps, photos, or personal data.
Go to Settings, then General, then Transfer or Reset iPhone, then tap Reset and choose Reset All Settings. Enter your passcode to confirm. Your iPhone will restart once after the reset completes.
You will need to re-enter your Wi-Fi password and reconfigure any custom settings afterward, but your photos, messages, and apps will remain intact.
Check Your Battery Health
Battery health is one of the most common yet overlooked causes of an iPhone that keeps restarting. As lithium-ion batteries age, they lose their ability to deliver consistent voltage during peak power demands. When the system detects a voltage drop, it triggers a protective restart to prevent data corruption.
Checking your battery health takes less than 30 seconds. Open the Settings app, tap Battery, then tap Battery Health and Charging. Look at the Maximum Capacity percentage. This number represents your battery’s current capacity compared to when it was new.
If the Maximum Capacity reads below 80%, your battery is officially considered degraded by Apple’s standards. At this level, the battery may not provide enough peak power for processor-intensive tasks, causing unexpected shutdowns and restarts. You will also see a message recommending battery service.
Many users on Reddit and Apple Support Communities report that their iPhone kept restarting until they replaced a battery reading between 70% and 79% capacity. After replacement, the restart loop stopped entirely. This makes battery health one of the first things to check if software fixes have not worked.
If your battery health reads above 85% and you still have restart issues, the problem is more likely software-related or involves a different hardware component. However, even a newer battery can have manufacturing defects, so do not completely rule it out.
To replace your battery, you have three options. Apple Store or Apple Authorized Service Provider (most reliable, uses genuine parts). Apple’s mail-in repair service. Third-party repair shop (often cheaper, but quality varies). If your iPhone is still under warranty or AppleCare+, the replacement may be free.
Advanced Methods: Recovery Mode and DFU Restore
When standard software fixes fail to stop your iPhone from restarting, you need more powerful tools. Recovery Mode and DFU (Device Firmware Update) Mode are the two most advanced methods for reinstalling iOS. Both require a computer with Finder or iTunes.
Recovery Mode vs DFU Mode: What’s the Difference?
Recovery Mode reinstalls iOS while keeping the bootloader intact. It can update or restore your iPhone and is the first advanced method to try. Recovery Mode is relatively simple to enter and works for most software-related restart issues.
DFU Mode bypasses the bootloader entirely and communicates directly with the hardware. This allows a complete firmware reinstall from the ground up, including the bootloader itself. DFU Mode is the most thorough software fix available and should be your last resort before seeking professional hardware repair.
How to Use Recovery Mode
Connect your iPhone to a computer and open Finder or iTunes. Perform the force restart button combination for your model, but keep holding the buttons past the Apple logo until you see the Recovery Mode screen.
When prompted on your computer, click Update first. This attempts to reinstall iOS without erasing your data. The download can take 15-30 minutes depending on your internet speed. If the Update fails or your iPhone still restarts afterward, return to Recovery Mode and click Restore this time.
Restore erases all data on your iPhone and installs a fresh copy of iOS. You can restore your data afterward from an iCloud or computer backup. Always try Update before Restore.
How to Use DFU Mode
DFU Mode requires precise timing on the button presses. The screen stays completely black in DFU Mode, which is how you know you have entered it correctly. Finder or iTunes will detect an iPhone in Recovery Mode even though the screen is black.
For iPhone 8 and newer: Connect to a computer. Press Volume Up, then Volume Down, then press and hold the Side button until the screen goes black. As soon as the screen goes black, press and hold both the Side button and Volume Down together for 5 seconds. After 5 seconds, release the Side button but keep holding Volume Down for another 10 seconds. The screen should remain black.
For iPhone 7 and 7 Plus: Hold the Side button and Volume Down together for 8 seconds. After 8 seconds, release the Side button but keep holding Volume Down for another 10 seconds.
For iPhone 6s and earlier: Hold the Home button and Sleep/Wake button together for 8 seconds. After 8 seconds, release the Sleep/Wake button but keep holding the Home button for another 10 seconds.
Once in DFU Mode, click Restore in Finder or iTunes. This completely reinstalls the firmware. After the restore completes, set up your iPhone as new first and test whether the restart issue is resolved before restoring your backup. If the phone still restarts with a fresh iOS install and no restored data, you almost certainly have a hardware problem.
Reading Kernel Panic Logs
Kernel panic logs can tell you exactly what is causing your iPhone to restart. These logs are generated every time the system encounters a critical error. You do not need to be a technician to read the basics.
To find them, go to Settings, then Privacy and Security, then Analytics and Improvements, then Analytics Data. Search for files starting with “panic-full.” These are kernel panic logs.
When you open a panic log, look for a few key terms. “thermalmonitord” indicates an overheating protection trigger. “watchdog timeout” means the system stopped responding. A “missing sensor” message suggests a disconnected or damaged hardware component like a microphone, camera, or ambient light sensor.
If your kernel panic logs consistently mention a specific hardware component, that component likely needs professional repair. For example, repeated mentions of a “torn flex cable” or “missing sensor data” point to physical damage on the logic board.
Prevention Tips to Avoid Restart Loops
Once you have fixed your iPhone, a few simple habits can prevent the restart loop from coming back. Our team has compiled these tips based on common patterns we have seen across hundreds of reported cases.
Keep iOS updated regularly. Apple releases patches for bugs that cause crashes and restarts. Do not skip updates, especially security patches and point releases. Set your iPhone to install updates automatically by going to Settings, General, Software Update, and enabling Automatic Updates.
Monitor your battery health monthly. Check Settings, Battery, Battery Health every few weeks. When the Maximum Capacity drops below 85%, start planning for a replacement. Do not wait until it falls below 80% and causes problems.
Maintain at least 5 GB of free storage. A full iPhone is an unstable iPhone. Regularly review your iPhone Storage settings and delete or offload items you no longer need. Photos, videos, and large message attachments are the biggest space hogs.
Be cautious with new apps and beta software. Read reviews before installing apps from unknown developers. Avoid installing iOS public betas on your primary device, as pre-release software is more likely to contain bugs that cause crashes.
Protect your iPhone from physical damage. Use a sturdy case to protect against drops that can damage internal components. Keep your phone away from water and extreme temperatures. If your iPhone does get wet, power it off immediately and let it dry completely before turning it back on.
Avoid extreme temperatures. Both extreme heat and extreme cold can cause battery issues and trigger protective restarts. Do not leave your iPhone in a hot car, and keep it out of direct sunlight for extended periods.
Use genuine or MFi-certified chargers and cables. Cheap, uncertified chargers can deliver inconsistent power that damages your battery over time. Stick with Apple-certified accessories or reputable brands with MFi certification.
When to Seek Professional Help?
If you have tried every software fix and your iPhone still keeps restarting, you are dealing with a hardware issue that requires professional repair. This is not a failure on your part. Some hardware problems simply cannot be fixed at home without specialized tools.
Signs that you need professional help include: the restart loop persists after a complete DFU Mode restore with a fresh iOS install, kernel panic logs consistently mention a specific hardware component, your battery health is above 85% but restarts continue, or the phone gets unusually hot during use.
For cost expectations, Apple Support diagnostics are free at any Apple Store or Authorized Service Provider. Battery replacement typically costs between $49 and $89 depending on your iPhone model. Logic board repair ranges from $150 to $400, and in some cases, Apple may offer a whole-unit replacement instead. Third-party repair shops often charge 30-50% less than Apple but may use non-genuine parts.
If your iPhone is still covered by AppleCare+ or the standard one-year warranty, repairs may be fully covered. Check your coverage status at checkcoverage.apple.com using your serial number before paying for any repairs.
FAQs
Why is my iPhone restarting again and again by itself?
Your iPhone keeps restarting due to either software issues (corrupted iOS, failed updates, problematic apps) or hardware problems (failing battery below 80% health, damaged charge port, faulty sensors). Software causes are more common and easier to fix. Check your battery health first, then try a force restart and iOS update. If the issue persists after software fixes, you likely have a hardware problem requiring professional repair.
How to fix iPhone restart loop?
To fix an iPhone restart loop, start with a force restart using the button combination for your model. If that fails, update iOS through Settings or Recovery Mode. Check battery health in Settings – if below 80%, replacement may be needed. Remove recently installed apps that might cause crashes. If the loop continues, use DFU Mode to reinstall iOS firmware completely. Hardware issues like a failing battery or damaged charge port require professional repair.
How much to fix iPhone reboot loop?
Fixing an iPhone reboot loop costs nothing if it is a software issue you resolve yourself. If you need professional help, Apple Support diagnostics are free, battery replacement costs around $49-89 depending on your model, and logic board repair can range from $150-400. Third-party repair shops may charge 30-50% less than Apple. If your iPhone is under warranty or AppleCare+, repairs may be covered at no cost.
How to fix phone constantly restarting?
To fix a phone that constantly restarts, force restart it first using the correct button combination for your model. Then check for and install any available iOS updates. Check your battery health – if it is below 80%, get it replaced. Remove any apps installed just before the problem started. If the phone keeps restarting, put it in Recovery Mode and restore iOS. As a last resort, use DFU Mode to completely reinstall the firmware, but this erases all data.
Knowing how to fix an iPhone that keeps restarting on its own gives you the power to diagnose and resolve the problem without immediately paying for repairs. Start with a force restart, then work through software updates, app checks, storage cleanup, and battery health assessment. If those steps do not solve it, Recovery Mode and DFU Mode offer deeper fixes for corrupted firmware. When all software methods fail, the issue is hardware-related and requires professional service. The key is to try fixes in order from simplest to most advanced, and always back up your data before attempting a restore.