Android has had a built-in tool for this for years, and most people never find it because the warning that fills the screen does not link to it. The order below starts with the things that cost you nothing and ends with the ones that log you out of apps.
The paths are the ones Google documents. Manufacturers move this menu around more than almost any other, so the section at the end covers the usual variations.
First: the screen Android built for exactly this
Open Settings, tap Storage, then Free up space. Google documents this in its page on freeing up storage on an Android device. It groups what is taking room and lets you select files to remove rather than guessing from app names.
Start here because it shows downloads, duplicates and large files you have genuinely forgotten about, which is almost always a bigger number than anything you would have deleted on purpose.
Second: cache, which is free to clear and comes straight back
For one app, open Settings, tap Apps, tap See all apps, tap the app, then tap Storage and cache. There are two buttons there and they are not interchangeable.
Clear cache deletes temporary data. Google notes that some apps may be slow the next time you open them, which is the entire cost: the app rebuilds what it needs. Nothing you created is touched.
Clear storage is the other one, and it resets the app to the state it was in when you installed it. You will be logged out and local data goes. It frees more and costs more, and it is rarely the right answer for a messaging app where the history lives on the device.
Clearing cache is also temporary by design. An app whose cache was two gigabytes will build it again, so if one app keeps coming back to the top of the list, the fix is inside that app's own settings, not this screen.
Third: Files by Google, for the junk nothing else catches
If the phone has Files by Google, open it, tap Menu, then Clean, then Clean on the junk files card, then Clear. Google documents this in its page on clearing junk files. It finds downloaded files, memes saved from chats and duplicate photos, which are the categories the Settings screen tends to miss.
If the menu is not where this says
Samsung puts the equivalent under Settings, then Battery and device care, then Storage, and its cleanup tool is branded differently. Xiaomi ships its own cleaner app. The Apps path for clearing one app's cache is the most portable part of this page and works nearly everywhere, even when the Storage screen does not look like Google's.
Some versions of Android removed the single button that cleared cache for every app at once. It is not hidden, it is gone, and the per app route is what replaced it.
Why the numbers never add up
The total Android reports as used will not match what you get from adding up the apps, and that is normal rather than a bug. The system partition, cached system files and files belonging to a second user profile all count toward the total without appearing in the list.
What none of this fixes
A phone that refills within days is syncing something: a camera set to save at full resolution with no cloud offload, a messaging app auto downloading every video, or a backup app writing locally. Clearing space buys a week and changes none of it.
If the phone is old enough that storage is only one of its problems, the more useful question is how much longer it gets security patches at all. When Pixel 6 support ends is that question answered with Google's own published dates.
Last updated October 4, 2026