Phone slow or hanging? 9 fixes that actually work (before you buy a new one)

A phone that hangs, lags or takes ages to open apps is one of the most common tech problems in the world. The good news: most of the time it can be fixed for free. Work through these steps in order — the first ones are quick and solve most cases.

1. Restart it

A restart clears memory, stops stuck background processes and finishes pending updates. If you never switch your phone off, restart it once a week.

2. Free up storage (aim for 15–20% free)

Phones slow down sharply when storage is nearly full, because the system has no room to work.

• iPhone: Settings → General → iPhone Storage. Offload apps you don't use, delete large videos (after backing them up) and empty Recently Deleted in Photos.
• Android: Settings → Storage (on Samsung: Settings → Battery and device care → Storage). Remove unused apps, old downloads and large videos, and empty the gallery's trash.

3. Install all updates

Updates fix bugs that cause lag and battery drain. Update the system first (iPhone: Settings → General → Software Update; Android: Settings → System → Software update), then update your apps in the App Store or Play Store.

Right after a big update, a phone can feel slower for a day or two while it re-indexes photos and files. Leave it on charge overnight before judging.

4. Find the app that's slowing everything down

One badly behaved app can drag the whole phone down.

• Check Settings → Battery: the apps at the top of the usage list are the busiest.
• Uninstall apps you don't recognise or haven't used in months.
• If the phone got slow right after you installed something, remove that app first.
• On Android, restarting in Safe mode (only built-in apps run) shows whether a downloaded app is the cause.

5. Cut down on widgets and live wallpapers

Live wallpapers, many home-screen widgets and "cleaner" or "booster" apps use memory and battery all the time. Remove them — cleaner apps often make things worse.

6. Check the battery

A worn battery can make a phone slower: some phones reduce peak performance when the battery can no longer deliver enough power.

• iPhone: Settings → Battery → Battery Health.
• Android: many phones show it under Settings → Battery (look for Battery health or Battery information), or in the maker's diagnostics app (for example Samsung Members).

If health is below about 80%, an official battery replacement often makes the phone feel close to new again — and costs far less than a new phone.

7. Keep it cool

Heat makes phones slow themselves down to protect the battery. Take off thick cases while gaming or charging, don't charge under a pillow or in the sun, and lower screen brightness.

8. Reset app preferences or clear app caches (Android)

On Android, clearing the cache of a large app (Settings → Apps → the app → Storage → Clear cache) can help. It doesn't delete your account or messages.

9. Back up and factory reset

If nothing else works, a factory reset removes years of leftover files and settings. Back up first (photos, chats, passwords, 2-factor apps), then reset, set it up as new and add apps back one by one.

When it's really time to replace it

Upgrading makes sense when:

• the maker no longer sends security updates for your model,
• apps you need say your phone or OS is no longer supported, or
• it's still slow after a factory reset and a healthy battery.

Not sure? Use our free Phone Life Check — it checks the official update promise for your model and tells you whether to fix or replace it. If it's time, the budget advisor picks three phones for your budget.