Free up Minecraft storage

Minecraft storage is mostly your worlds, then resource packs, behavior packs, and screenshots. Worlds are your saves. They are not cache. Do not delete a world to free space unless you already copied it somewhere else.

See how much space Minecraft is using

iPhone

Open the iPhone Settings app.
Tap General > iPhone Storage.
Tap Minecraft.

Android

Open your phone Settings > Apps (or Apps and notifications).
Tap Minecraft.
Tap Storage or Storage and cache.

Documents and Data is often worlds. Treat that number as your saves until you prove otherwise.

Back up worlds before you delete anything

Open Minecraft and go to the worlds list.
That list is user data. A world you remove is gone from this phone.
Copy worlds you care about to Files, a computer, or a cloud folder first.
On Android, worlds also live under the Minecraft folder in Files. Copy the world folder, do not clear it as junk.

Realms and some server worlds can be re-downloaded. Local single-player worlds cannot. Never treat worlds as cache.

Remove resource packs you added

Open Minecraft Settings.
Open Storage or Global Resources (wording depends on edition).
Remove resource packs and behavior packs you installed and no longer use.
Cached packs from multiplayer servers can go. Leave packs that a world still needs.

Screenshots and imported skins are also local files. Delete those only if you do not want them.

Cached server data

Joining a realm or server can leave a cached copy of that world. Removing that cache is fine if you can rejoin the server. It is not the same as deleting a world you built on this device.

Clear Minecraft cache on Android

Open your phone Settings > Apps > Minecraft.
Tap Storage or Storage and cache.
Tap Clear cache.

Do not tap Clear storage / Clear data unless you mean to reset Minecraft on this phone. Clear data wipes local worlds, packs, and screenshots. That is not a cache clear.

iPhone does not offer a separate Minecraft cache button. Use the in-app steps on this page, or offload the app in iPhone Storage if the system total stays high.

Reinstall the app if storage is still high

If you already cleaned media and Minecraft still looks huge, a fresh install can clear leftover cache and temp files that are hard to reach by hand.

Copy your worlds off this phone first. Worlds are local user data, not cache. Resource packs you added and screenshots also stay on the device unless you backed them up.
Delete the app from your phone.
Restart your phone.
Install Minecraft again from the App Store or Google Play.
Sign in and restore from backup if the app offers it.

This often frees a lot of space. You may need to download some media again after restore.

What to do next

After Minecraft is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.