Performance
Why is my phone so slow? The 7 real causes
"It's just old" is the least useful diagnosis in phone repair. Chips don't wear out and get slower; something specific is holding your phone back. Here are the seven causes we actually find, roughly in the order worth checking. The first four are free to fix tonight.
1. Storage that's nearly full
This is the biggest one, and the most ignored. Phone storage needs free space to work in: to write caches, to shuffle files, to install updates. Squeeze it below about 10% free and everything slows — apps take longer to open, photos take a beat to save, the keyboard lags.
Fix it: check Settings → General → iPhone Storage or Settings → Storage on Android. Clear downloaded videos and podcasts, offload apps you don't use, and get your photo library backed up to the cloud or a computer so you can remove local copies. Aim for 10–15% free, and notice the difference the same day.
2. A restart you haven't done in months
Phones are meant to run for weeks, but a process stuck in a loop will happily eat a core and a chunk of memory until something clears it. If you can't remember the last time your phone was properly off, turn it off, wait ten seconds and turn it back on before you try anything else.
3. Background apps and widgets doing too much
Social and shopping apps refresh in the background, widgets poll for updates, and a few badly-behaved apps do it constantly. Turn off background refresh for anything you don't need live (Settings → General → Background App Refresh on iPhone; Battery → Background usage limits on most Androids), trim your widgets, and check the battery screen for an app using far more than its share — that's usually your culprit.
4. A browser carrying a year of tabs and cache
Hundreds of open tabs and a bloated cache make the browser slow, and because the browser is where most people spend their time, that feels like a slow phone. Close the tabs, clear the cache, and judge again.
5. A worn battery (the most common hardware cause)
An ageing battery can't deliver current in bursts, so the phone deliberately caps its peak speed to avoid shutting down. That's why an old phone can feel fine reading email and fall apart the moment you open the camera. If the phone is 2–3 years old, shuts down early, or shows battery health under 80%, this is very likely your answer — and it's a $59 fix, not a new phone.
How an old battery slows your phone down →
6. Heat, and the throttling that follows
A hot phone slows itself on purpose to protect its components. If yours runs warm sitting on the desk, something is causing it: a stuck app, a poor-quality charger, a swollen battery, a damaged screen, or moisture from an old spill. Working in direct sun on a 35°C day will do it too, and that one's not a fault.
How a damaged screen makes your phone run hot →
7. A new operating system on older hardware
Sometimes it really is the update. A major OS release is built for the current generation, and on a five-year-old phone the animations and background services cost more than they used to. You can claw a lot of it back by turning on Reduce Motion and Reduce Transparency (iPhone: Settings → Accessibility → Motion / Display & Text Size; Android has equivalents under Accessibility), which makes the interface feel markedly snappier.
The ten-minute tune-up
- Restart the phone.
- Free up storage until you have 10–15% spare.
- Update the OS and your apps (yes, really — many slowdowns are bugs that got fixed).
- Turn off background refresh for apps you don't need live.
- Check the battery screen for one app using far more than the rest.
- Check battery health.
If it's still slow after all that, it's hardware — and hardware is what we do.
When it's worth bringing in
Bring it to us if the phone is hot when it shouldn't be, shuts down with charge left, is slow immediately after a full charge, or got sluggish right after a drop or a spill. We'll test the battery under load, check for heat and moisture damage, and tell you what it needs — including telling you when the honest answer is that it isn't worth fixing.