How to Fix Galaxy S25 Ultra Stuck on Boot Loop After Update
If your Galaxy S25 Ultra started having this problem after the latest One UI update, the cause is usually a software conflict, stale temporary files, changed settings, or an app that no longer behaves correctly with the new build.
The steps below focus on practical fixes you can try before booking repair. Work through them in order, because the simpler steps often solve the issue faster.
Why this happens
Problems like this often show up after an update changes power management, radios, camera behavior, notifications, or app permissions. Old cached data and unfinished post-update background tasks can then trigger the exact symptom you are seeing.
Fix #1: Force restart the phone
Press and hold the Side key and Volume Down key for about 10 to 15 seconds. If the phone gets past the Samsung logo after the forced reboot, a temporary startup crash was likely blocking the boot process.
Fix #2: Remove the charger and accessories
Disconnect USB-C cables, MagSafe-style rings, cases with magnets, USB hubs, and other accessories before restarting again. A bad cable, unstable charger, or accessory conflict can interrupt the startup routine after an update.
Fix #3: Boot into Safe Mode if the phone can reach the lock screen
If the phone boots far enough, restart into Safe Mode and remove recently updated launchers, battery apps, VPNs, or cleaning tools. Third-party apps often trigger restart loops right after a firmware change.
Fix #4: Wipe the cache partition in Recovery Mode
Boot into Android Recovery and wipe the cache partition. This removes stale temporary system files that can keep the device trapped on the Samsung logo or restarting repeatedly.
Fix #5: Check for another software update in recovery or Smart Switch
Samsung sometimes pushes quick follow-up patches after large updates. Install any available maintenance release because the boot loop may be tied to the previous build.
Fix #6: Free up storage if the phone eventually starts
If the device can boot intermittently, delete large downloads, duplicate videos, and unused apps. Low free storage can prevent Android from finishing optimization after an update.
Fix #7: Factory reset only after backing up what you can
If the boot loop continues after cache wiping and Safe Mode checks, perform a factory reset from recovery. Set the phone up as new first so you can confirm the update issue is gone before restoring everything.
Fix #8: Contact Samsung support if the phone still boot loops
If a clean reset does not fix the problem, the update may have exposed deeper firmware corruption or storage failure. Samsung support or a service center can run additional diagnostics.
More Galaxy S25 help
For more exact-match troubleshooting guides, visit the Galaxy S25 hub page.