Why Does My Android Phone Randomly Restart? 6 Fixes (2026)
A phone that restarts itself in the middle of a call, a game, or while sitting untouched on a table is more than just annoying — it usually means something specific is going wrong, and most causes are fixable without a trip to a repair shop. Here are the six most common reasons Android phones randomly reboot, in the order you should check them.
1. A Recently Installed App Is Crashing the System
The most common cause by far is a single misbehaving app, especially one installed or updated recently. Some apps request deep system-level permissions and, when they crash, can take the whole phone down with them.
How to check: Boot into Safe Mode (press and hold the power button, then long-press “Power off” until you’re prompted to restart in Safe Mode). If the phone stops restarting in Safe Mode, a third-party app is the cause. Uninstall recently added apps one at a time to isolate the culprit.
2. Overheating Triggers a Protective Restart
Modern Android phones include thermal protection that force-restarts the device if internal temperature climbs too high, protecting the battery and processor from damage. This is common during gaming, navigation with GPS and screen on, or charging in direct sunlight.
Fix: Remove the case while gaming or charging, avoid direct sunlight, and close demanding apps if the phone feels hot to the touch. If restarts only happen during heavy use, this is very likely the cause.
3. A Software Update Is Pending or Corrupted
Sometimes a partially downloaded or corrupted system update causes instability that manifests as random reboots until the update either completes or is rolled back.
Fix: Check Settings > System > System Update. If an update is available, install it fully. If problems started right after an update, a lot of manufacturers push a follow-up patch within days — check again in a week.
4. Battery Health Has Degraded Significantly
As covered in our guide on extending smartphone battery life, an aging battery can develop voltage delivery problems. When the battery can’t supply stable power under load, the phone’s power management system can force a restart rather than risk a crash or damage.
How to check: If restarts happen mostly when the battery is below 20-30%, or during demanding tasks even at higher percentages, battery degradation is a likely cause. Many Android phones show a battery health estimate under Settings > Battery.
5. Storage Is Nearly Full
Android needs free storage space to manage background processes, cache files, and system operations. When storage drops below roughly 10% free, some phones become unstable and may restart unexpectedly.
Fix: Go to Settings > Storage and clear cached data, delete unused apps, or move photos/videos to cloud storage or a computer. Aim to keep at least 10-15% of total storage free.
6. A Hardware Fault (Charging Port, Power Button, or Motherboard)
If none of the above resolve the issue, the cause may be physical: a damaged power button that’s intermittently stuck, a faulty charging port causing power fluctuations, or in rarer cases, a motherboard-level fault.
How to check: Note whether restarts happen more often while the phone is charging or immediately after unplugging — this points to the charging port or battery connector. A power button that feels stiff, sticky, or requires unusual pressure is worth having inspected separately.
If a hardware fault is suspected, a professional diagnostic (typically under £30 and often credited toward any repair) is the fastest way to confirm what’s actually happening internally, rather than guessing further.
When to Try a Factory Reset
If you’ve ruled out overheating, storage, and an obvious app, and updates are current, a factory reset (after backing up your data) resolves the majority of remaining software-level causes. Go to Settings > System > Reset options > Erase all data. This is a bigger step, so it’s worth trying the six causes above first.
Tracking Restarts to Speed Up Diagnosis
If the cause isn’t obvious after checking the items above, keeping a simple log for a few days makes diagnosis much faster — note the time of each restart, what you were doing (charging, gaming, idle), and roughly what battery percentage the phone was at. Patterns that emerge from even three or four logged restarts often point clearly toward one of the six causes above, saving you from randomly trying fixes one at a time without knowing which is actually addressing the real trigger.
A Simple Habit That Helps Long-Term
Beyond diagnosing a current issue, it’s worth periodically restarting your phone once every week or two even without symptoms, since this clears accumulated background process buildup that can otherwise contribute to instability over time. This alone won’t fix a hardware fault, but for software-related causes, it’s a low-effort habit that reduces how often you encounter unexpected restarts in the first place.
When to Involve a Repair Shop Instead
If you’ve worked through all six causes above over a few days and restarts continue with no clear pattern, it’s more efficient to have a professional run a full diagnostic than to keep guessing indefinitely. Most shops can identify a power-related hardware fault within 30-60 minutes using tools that measure actual voltage delivery under load, which isn’t something you can replicate through software troubleshooting alone.
Frequently Asked Questions
Is it normal for a phone to restart occasionally? An occasional restart tied to a specific app crash isn’t unusual, but multiple unprompted restarts per day, especially with no clear trigger, points to one of the causes above.
Can a cheap charger cause random restarts? Yes — an uncertified charger delivering inconsistent voltage can confuse the phone’s power management system, occasionally triggering a restart. Switching to a certified charger is a simple test.
Does a factory reset fix a hardware problem? No. If restarts continue identically after a full factory reset with no apps reinstalled yet, the cause is very likely hardware, not software, and professional inspection is the next step.
How do I know if it’s the battery specifically? If restarts correlate with low battery percentage or heavy processor use (gaming, camera, navigation) rather than happening randomly at any charge level, battery degradation is the most likely explanation — see our Samsung Galaxy battery replacement guide for next steps.
Can overheating cause permanent damage even if the phone restarts to protect itself? Repeated severe overheating events, even with protective restarts, can accelerate long-term battery degradation over months and years, making it worth addressing root causes (case removal during charging, avoiding direct sun) rather than treating occasional protective restarts as harmless.
For more diagnostic guides like this one, browse our Tips & Maintenance category.
External reference: Android’s official battery and power management documentation{:target=”_blank” rel=”nofollow noopener”} explains how thermal and power throttling decisions are made at the system level.