Why does my phone restart by itself?

It can be frustrating when your phone suddenly restarts or turns off by itself without warning. A random reboot here and there may not be cause for concern, but if it’s happening frequently, there are some steps you can take to try to fix the issue.

Quick Answers

Here are some quick answers to common questions about random phone reboots:

  • Overheating – If your phone is overheating, it may reboot to cool down.
  • Buggy software – Bugs or glitches in the phone’s software can cause reboots.
  • Too many apps – Having too many apps and processes running can overload the phone and cause reboots.
  • Outdated software – An outdated OS or apps need updating.
  • Hardware issue – Faulty hardware like the battery or logic board can trigger reboots.
  • Incorrect settings – Incorrect settings like display or power management settings could be factors.

What causes sudden restarts?

There are several potential causes for random restarts on smartphones:


One of the most common reasons a smartphone may suddenly restart is overheating. Mobile phones generate heat from processor intensive tasks, long periods of use, apps running in the background, hot environments, or charging.

If the internal temperature gets too high, the phone may automatically reboot as a protective measure to cool itself down. A random reboot from overheating usually only occurs once until the phone cools to a safe temperature again.

Buggy software/firmware

Bugs, glitches or inconsistencies in the phone’s software and firmware can also trigger an unexpected restart. Issues with the operating system, apps or drivers may cause the phone to freeze, lock up or spontaneously reboot.

Software bugs occur frequently with major operating system (OS) updates or new phone models when the code isn’t fully optimized yet. The bugs causing reboots are usually fixed in subsequent software updates.

Too many apps/processes running

Today’s smartphones pack a ton of processing power. But having too many apps and background processes running can put a strain on the phone’s available RAM and cause slowdowns or restarts. Closing unused apps regularly can help prevent overload.

Some power hungry apps that use GPS, mobile data or GPU resources in the background could also potentially trigger a reboot if there are too many running simultaneously.

Outdated software

Failing to keep your phone’s OS and apps updated could make random reboots more likely. Updates often contain fixes for bugs and performance issues that may be causing crashes and restarts.

Using old unsupported OS versions risks incompatibilities and other glitches that lead to stability issues. It’s best to stay current with major OS and app updates from Google, Samsung, Apple, etc.

Failing or faulty hardware

Faulty hardware like a degraded battery, faulty RAM chip or defects with the logic board can lead to random reboots in some cases. As electronic components wear out over time, inconsistencies in power delivery or component failures may cause the phone to spontaneously reset or turn off.

Issues like loose connections or a faulty power button are other physical defects that could trigger an unexpected reboot though they are less likely.

Incorrect settings

Certain device settings being configured incorrectly can also contribute to random restarts in some scenarios:

  • Display settings – An incorrect screen resolution or animations/transitions turned off could cause stability issues.
  • Power saving settings – Aggressive power saving modes may cause apps/processes to close abruptly and restart the phone.
  • Task killers – 3rd party task killer apps can be too aggressive and restart the device.
  • Launchers – Buggy 3rd party launchers may not play nice with the OS and cause conflicts.

Resetting various settings to default can help identify if any customized configs are problematic.

How to troubleshoot random restarts

If your phone continues restarting spontaneously, here are some steps to troubleshoot the issue:

Check for overheating

Feel along the back and sides of the phone after a reboot to check if it seems abnormally hot. A warm phone may indicate overheating.

Remove the phone case to dissipate heat better. Also avoid prolonged sun exposure which can heat the device. The phone should cool down after a few minutes.

Monitor running apps and usage

Take note of which apps are open before a restart. Check the memory and CPU usage in the OS settings. Too many demanding apps running concurrently may overload the phone.

Watch for patterns like restarts during gaming or video calls which use more resources. Close background apps you aren’t actively using.

Update software

On your phone’s settings, check for any pending system software, OS, security and app updates. Install available updates which often fix bugs causing stability issues.

Restart the phone after updating and monitor if reboots continue. You may need to perform multiple update cycles over weeks as new patches are rolled out.

Reset device and uninstall apps

Consider resetting your device to factory settings which wipes any problematic customized settings that may be causing conflicts. You’ll have to reconfigure the phone and reinstall apps after resetting.

Alternatively, try uninstalling recently added apps one by one to see if any particular app triggers the reboots. Narrow it down by uninstalling apps added around the time issues started.

Check for hardware defects

Inspect your phone thoroughly for signs of external damage like dents, cracked screen or water damage which may indicate a hardware fault.

Check if the battery is swollen or leaking which occurs when batteries degrade over time. Test to see if reboots happen when running on battery versus wall power.

Schedule a diagnostics appointment at a phone repair shop. They can run tests to check battery health, CPU performance and other components. However, repair costs may approach the price of a new phone.

Replace battery or device

If you’ve ruled out software issues, the random restarts are likely due to aging lithium-ion battery or degrading internal hardware components. These components gradually degrade over a phone’s lifetime with normal use.

For an older phone, replacing the battery may provide a temporary fix for random reboots. However, other components will continue degrading, so it may be time to replace the phone entirely if it’s over 3-4 years old.

How to prevent random restarts

While spontaneous reboots may be unavoidable as a phone ages, there are steps you can take to reduce occurrences:

  • Avoid overheating – Don’t leave phones in hot cars or direct sun. Provide ventilation.
  • Close unused apps – Apps running in the background put more load on the phone.
  • Limit gaming/video calls – Processor-intensive apps generate more heat.
  • Use a case – Cases dissipate heat better than bare phones.
  • Keep phone updated – Install the latest OS, security and app updates.
  • Reset device occasionally – Resets remove accumulated glitches over time.
  • Replace battery after 3 years – Old batteries contribute to stability issues.

Also be sure to backup data regularly in case random restarts result in data loss.

When to be concerned about frequent restarts

An occasional random reboot may not be worrisome. However, if your phone is restarting repeatedly in a short period, it likely indicates a bigger underlying problem.

Frequent reboots that occur multiple times a day may stem from more serious system instability, overheating or hardware degradation issues. The constant abrupt power cycling could potentially corrupt your phone’s operating system over time.

Excessive random reboots can also lead to unexpected data loss or app crashes before you get a chance to save information. Take notes on the frequency and circumstances of the reboots.

If reboot issues started after installing a particular app or OS update, that may reveal the cause. Persistent reboots after trying standard troubleshooting warrant further inspection by a repair technician.

When to reset or replace your phone

If your phone continues randomly restarting despite troubleshooting, it may be time for a factory reset or phone replacement.

A factory reset (backup data first!) can fix software issues causing reboots. This gives your phone a clean slate if glitches have accumulated over time.

But if your phone is older, a reset provides only temporary relief before problems resurface. Frequent reboots often mean hardware like the battery or logic board components are wearing out.

If your phone is over 3 years old, replacement may be the most cost-effective option compared to the cost of phone repairs. With modern phone innovations every year, a new phone also gives you latest features and specs.

Use the following table as a guide on when to reset or replace your phone due to reboot issues:

Phone Age Troubleshooting Steps Reset or Replace?
0-2 years Update software, uninstall apps, reduce background usage Try resetting phone
2-3 years Replace battery, update and reset phone Consider replacing phone
3-4 years Factory reset if not done already Strongly consider replacement
Over 4 years Reset won’t resolve hardware degradation Replace phone

Key takeaways

  • Common reboot causes include overheating, software bugs, too many apps, outdated OS, faulty hardware.
  • Troubleshoot by checking for overheating, monitoring apps, updating software, factory reset.
  • Prevent reboots by avoiding heat, closing apps, keeping phone updated, replacing battery.
  • Frequent reboots may require reset or replacement, especially if phone is over 3 years old.
  • Back up data regularly in case reboots result in data loss.


The occasional random restart generally isn’t a major issue. But frequent reboots can indicate more serious problems requiring troubleshooting and maintenance.

To stop frustrating spontaneous restarts, keep your phone updated, monitor resource usage, and restart/replace once hardware degrades. With proper care and troubleshooting, you can minimize sudden reboots and extend your phone’s lifespan.

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