Why Does My Phone Keep Restarting? How to Fix It

A phone that reboots on its own is one of the most unsettling faults to live with, because it usually strikes mid-task and rarely leaves an obvious clue. The good news is that random restarts almost always trace back to a short list of causes: a pending system update, one misbehaving app, a nearly full storage drive, heat, or a battery that is simply worn out. Genuine hardware failure exists too, but it sits near the bottom of the list. This guide walks through the fixes in the order that solves the most cases first, so you can stop at the step that works instead of jumping straight to a factory reset. Where Android and iPhone differ, we call it out.

Key Takeaways

• Most random restarts are software, not hardware. Start with pending updates and storage before you assume the phone is dying.
• A single bad app is the most common culprit. Android’s Safe Mode lets you prove it in minutes; iPhone has no official Safe Mode, so you test by removing recently added apps.
• Heat and a swollen or degraded battery cause the phone to shut down to protect itself, which looks identical to a random restart.
• Reset the phone’s settings before you reset the whole device. “Reset all settings” keeps your photos and apps; a factory reset erases everything.
• Always back up before a factory reset, and treat physical or water damage as a repair job, not a software fix.

1. Install pending updates and restart cleanly

Manufacturers push updates specifically to patch the bugs that trigger reboot loops, so an out-of-date phone is the single most common starting point. A stale update can also leave the system half-patched and unstable.

1. On Android, open Settings, then System, then Software update (the exact path varies by brand) and install anything offered.
2. On iPhone, open Settings, then General, then Software Update, and install the latest iOS.
3. Update your apps too: open the Play Store or App Store, go to your account, and update all.
4. Once updates finish, power the phone fully off, wait ten seconds, and turn it back on so the new code loads from a clean state.

If the phone restarts too quickly to reach these menus, connect it to Wi-Fi and a charger and leave it alone; updates often download and stage on their own once power and network are stable.

2. Free up storage space

When internal storage runs low, the operating system has no room for the temporary files it constantly writes, and apps and system processes crash, freeze, or force a reboot. This is easily overlooked on older phones packed with photos and video.

1. Check your free space: Settings, then Storage on Android; Settings, then General, then iPhone Storage on iPhone.
2. Aim to keep several gigabytes free. If you are near full, delete large videos, clear downloads, and offload apps you rarely open.
3. On Android, clearing the cache of a heavy app (Settings, then Apps, pick the app, then Storage, then Clear cache) reclaims space without deleting your data.
4. Move photos and videos to cloud storage or a computer, then remove the local copies.

Restart the phone after clearing space and watch whether the reboots stop over the next hour of normal use.

3. Track down a misbehaving app

A single buggy or incompatible app is the most frequent cause of repeated restarts, especially if the trouble began right after you installed or updated something. The approach differs by platform.

1. Android, use Safe Mode: press and hold the power button, then touch and hold the “Power off” option until “Reboot to safe mode” appears, and confirm. Safe Mode loads the phone with all third-party apps disabled. If the restarts stop in Safe Mode, an app you installed is the cause.
2. Back in normal mode, uninstall apps one at a time, newest first, testing after each removal until the reboots stop.
3. iPhone: iOS has no official Safe Mode unless the device is jailbroken, so you test manually. Delete or offload the app you added just before the problem started, then any others you have updated recently, checking stability after each.
4. Watch for apps that run constantly in the background, such as VPNs, cleaners, or battery boosters, as these are common offenders.

Once you identify the culprit, leave it uninstalled and report the bug to the developer, or wait for a fixed version before reinstalling.

4. Let the phone cool down and check for overheating

Phones deliberately restart or shut down when the processor or battery gets too hot, as a self-protection measure. If reboots cluster around gaming, video, navigation, fast charging, or hot weather, heat is the likely trigger rather than a software bug.

1. Remove any thick case, take the phone out of direct sun, and let it sit and cool for fifteen minutes before using it again.
2. Avoid using the phone heavily while it charges, which stacks two heat sources.
3. Close demanding apps and lower screen brightness during long sessions.
4. If the phone feels alarmingly hot to the touch even at rest, stop charging it and treat that as a battery warning sign (see the next step).

5. Check the battery and charging port

An aging battery struggles to deliver steady power, and a sudden current dip can drop the phone into an instant restart, most noticeably when the charge is low or the load is high. A dirty or damaged charging port can do the same by momentarily bridging or cutting contacts.

1. On iPhone, check Settings, then Battery, then Battery Health & Charging; a Maximum Capacity well below 80 percent points to a tired battery.
2. On Android, battery health tools vary by brand; look under Settings, then Battery, or use the manufacturer’s diagnostics app.
3. Inspect the charging port with a light and gently clear lint or debris with a wooden toothpick, never metal.
4. Try a different official cable and charger to rule out a failing accessory.
5. If the phone or battery is visibly swollen, stop using it immediately and take it to a technician.

A worn battery is a physical part, so if capacity is low the real fix is a professional replacement, not more troubleshooting.

6. Reset settings (not your data)

If a bad configuration is behind the reboots, resetting settings clears it without touching your photos, messages, or apps. This is the sensible middle step before a full wipe.

1. On iPhone, go to Settings, then General, then Transfer or Reset iPhone, then Reset, and choose “Reset All Settings.” This keeps your data but returns system settings to default.
2. To fix connection-related instability, “Reset Network Settings” from the same menu is worth trying first.
3. On Android, open Settings, then System, then Reset options, and use “Reset app preferences” or “Reset Wi-Fi, mobile & Bluetooth” before anything more drastic.
4. Restart and test normally for a day before deciding whether to go further.

7. Back up, then factory reset as a last resort

A factory reset reinstalls a clean copy of the operating system and clears deep software corruption that nothing else reaches. It also erases everything on the phone, so this is genuinely the last software step.

1. Back up first. On iPhone, use iCloud Backup (Settings, your name, iCloud, iCloud Backup) or back up to a computer. On Android, use Google One backup (Settings, System, Backup) or your brand’s tool.
2. Confirm the backup actually completed before you wipe anything; a reset with no backup means permanent data loss.
3. Erase: iPhone via Settings, General, Transfer or Reset iPhone, then “Erase All Content and Settings”; Android via Settings, System, Reset options, then “Erase all data (factory reset).”
4. Set the phone up as new first and use it for a day before restoring your backup. If it stays stable clean but reboots return after you restore, a backed-up app or setting is to blame.

8. Rule out physical and water damage

If the restarts began after a drop, a spill, or exposure to rain, no software fix will hold, because the fault is in the hardware. Moisture on the logic board or a loosened connector produces exactly this kind of intermittent reboot.

1. Stop charging a phone you suspect got wet, and do not try to speed-dry it with heat.
2. Look for a cracked screen, bent frame, or a triggered liquid-contact indicator.
3. Book a repair with the manufacturer or a reputable technician rather than continuing to power-cycle the device, which can make damage worse.

Frequently asked questions

Why does my phone keep restarting even after a factory reset?

If reboots survive a clean factory reset where you set the phone up as new and did not restore a backup, the cause is almost certainly hardware, most often the battery, the charging port, or a board-level fault. At that point a repair or battery replacement is the realistic fix rather than more software troubleshooting.

Does Android have a Safe Mode and does iPhone?

Android has a built-in Safe Mode that boots with third-party apps disabled, which makes it the fastest way to prove an app is at fault. iPhone has no official Safe Mode unless the device is jailbroken, so on iOS you test by removing recently installed or updated apps one at a time instead.

Will resetting settings delete my photos and apps?

No. “Reset All Settings” on iPhone and the equivalent reset-preferences options on Android only return system settings to default; your photos, messages, and installed apps stay in place. A factory reset is the one that erases everything, which is why you back up before doing it.

My phone gets hot then restarts. Is that a virus?

Almost never. Heat-triggered restarts are usually the phone protecting itself during heavy use, fast charging, or hot weather, or a sign of a degrading battery. Let it cool, remove the case, and check battery health before worrying about malware; if you are still concerned, use Safe Mode on Android to see if a background app is the real cause.

How much free storage should I keep to avoid restarts?

There is no official figure, but keeping several gigabytes free gives the system room for the temporary files it writes constantly. Phones that sit nearly full are far more prone to crashes, freezes, and unexpected reboots, so clearing space is one of the cheapest fixes to try.