What is app cache on Android? Clear cache vs clear storage

What is the difference between Clear cache and Clear storage?

Android's own help text puts it plainly: Clear cache "deletes temporary data", while Clear storage "permanently deletes all app data" and you should try deleting data inside the app first. Chat apps are the risky case, because clearing storage on an app without a backup can wipe message history.

Android also clears caches on its own when storage runs low. The system removes cached files from apps first, so a phone that is almost full may already have trimmed them, and the saving from clearing by hand will be smaller than the app's Storage screen suggested yesterday.

Which apps build the biggest caches?

• Social and video apps that pre-load feeds and clips; caches of 1 to 3 GB are common.
• Browsers, which store pages, images and scripts from every site you visit.
• Maps and music, although offline maps and downloaded songs are data, not cache, and clearing cache leaves them alone.
• Gallery and photo apps, which keep previews; see thumbnail cache.

Caches grow back. An app that lost 2 GB of cache today may rebuild most of it within a week of normal use, so clearing cache is a short-term fix rather than a cure for a full phone.

To find the heaviest caches, open Settings > Apps, sort by size if your phone allows it, and open the top few to compare the Cache figure with the app's total.

When is clearing cache worth it?

Clear the cache of one app when it misbehaves, shows stale content or has an unusually large cache in its Storage screen. Clearing every app's cache at once, which some "booster" apps promise, gains little and makes everything slower to open for a while. Files by Google's Clean tab also offers a junk-files card that clears app caches you can safely remove.

Photos and videos are usually a much bigger slice of storage than caches. A clean of duplicates, forwards and failed shots tends to free several times more space, and it stays freed. The booster app page explains why one-tap cleaners overpromise, and phone storage full lists bigger wins.

A quick test: note an app's cache size, clear it, and check again after a week.