Should I clear the cache, clear the data, or reinstall an app?

These three options are offered in slightly different places on iOS and Android, and the naming is genuinely confusing. Android puts clear cache and clear storage side by side in the app's settings entry. iOS mostly does not expose a cache control at all, so the practical iOS ladder is: offload, then delete and reinstall, with some apps offering their own clear-cache button inside their settings. Knowing which layer each action cuts saves you from being logged out of everything for no reason.

Step by step

1. Start with the cache, because it is free.The cache holds thumbnails, downloaded images, rendered pages and temporary working files — everything the app can fetch or rebuild. Removing it costs you nothing except a slightly slower first load. On Android it is a button in the app's entry in settings; on iOS look inside the app's own settings for a storage or cache option.
2. Restart the phone after clearing.Some apps hold a broken state in memory that survives the cache clear. A restart is ten seconds of your time and eliminates the ambiguity before you escalate to something destructive.
3. Before clearing data, work out what lives only in this app.Ask what would be gone if the app were new: are your notes synced to an account, are your game saves tied to a login or only to the device, are your settings and filters reproducible, is there a two-factor authenticator inside it? Authenticator apps in particular can lock you out of accounts permanently if you wipe them without exporting first.
4. Clear the data or storage as the second step.This resets the app to how it arrived. Logins, preferences, downloaded content and local files go. Anything the app stores on its own servers comes back when you sign in again. On Android this is 'clear storage'; on iOS the nearest equivalent is deleting and reinstalling.
5. Reinstall when the program itself is suspect.If the app crashes on launch, will not update, behaves differently from the same app on another phone, or was interrupted mid-update, reinstalling replaces the program files as well. It is the same data cost as clearing storage plus a download.
6. Check for an app update before and after.A crash that started this week is very often a bad release, and the fix is a newer version rather than anything you do to your copy. Equally, a stalled half-applied update produces symptoms that look exactly like corruption.
7. If nothing works, look outside the app.An app that will not load anything when other apps work fine is usually a network, date-and-time, or account problem rather than an app problem. A wrong system clock breaks secure connections and produces baffling app errors on both platforms.

Common mistakes

• Clearing the storage of an authenticator app — The codes are generated from secrets stored on the device. Wiping them without a transfer or export can lock you out of accounts with no route back except each service's account-recovery process.
• Reinstalling a paid app expecting to pay again — You will not — purchases are attached to your store account, not the install. This fear stops people doing the one thing that would fix the problem.
• Clearing data on the phone's messaging or dialler app — On some Android phones this can take message history with it. Back the messages up first, or restrict yourself to clearing the cache there.
• Treating a cache clear as a fix for storage pressure — The app rebuilds the cache within days. It is a troubleshooting step, not a storage strategy — for storage, address the downloads and media instead.

Questions people ask