Android slow after an update: why it happens and what to do
A phone is commonly slow for the first day or two after a system update because it re-optimises apps and rebuilds indexes in the background. If it is still slow after a week, look for apps the update changed or re-enabled, low storage and background activity.
What is happening after an update
- Installed apps are recompiled and optimised for the new system version.
- Photo, file and search indexes are rebuilt.
- The Play Store updates apps to versions that suit the new release.
- Sync, backup and widgets catch up, and battery statistics start again.
What to try first
- Leave the phone plugged in on Wi-Fi overnight so background work can finish, then restart it once.
- Check that the phone has free storage. A nearly full phone slows down badly.
- Update your apps in the Play Store and install any second, smaller system update.
- Restart in safe mode to see whether an installed app is the cause: if the phone is fast in safe mode, an app you installed is to blame.
Find out what the update changed
Updates can add apps, re-enable ones you had disabled and change how much each app costs. The slimdroid tool can compare two scans and list new packages, re-enabled packages and cost that moved. You need an earlier scan from before the update; if you do not have one, scan now and again after the next change. Scans are saved in your browser, not uploaded.
When it is something else
- Storage almost full: see Android phone slow? Find what is slowing it down.
- The battery drains quickly as well: see what is draining my Android battery.
- One app is slow: update it, clear its cache, or reinstall it.
- Still slow after a week: back up and, as a last resort, factory reset.
How long is an Android phone slow after an update?
Usually a day or two while background optimisation finishes. If it is still slow after about a week, treat it as a real problem and investigate.
Can an update re-enable apps I disabled?
A major update can re-enable or reinstall some disabled apps, so scan again afterwards and disable them again if you want them off.
Should I factory reset after an update?
Not as a first step. Try the quick fixes, then compare scans. A reset is the last option because it removes your disabled-app changes along with everything else.