OBB files
Also known as: OBB, expansion files, game data Android
OBB files are APK expansion files that hold the large assets — game graphics, audio, and levels — that do not fit inside an app’s install package. They live in Android/obb on internal storage and can be several gigabytes per game.
- Expansion files holding large game assets
- Stored in Android/obb on internal storage
- Removed cleanly by uninstalling the app, not by hand
Where OBB files live
OBB data sits in Android/obb/[package name] on internal storage, alongside the app’s Android/data folder. Each large game or app gets its own subfolder named after its package.
These files are downloaded the first time you open a game, separately from the store install, which is why a "small" download can balloon into gigabytes after launch.
Can you delete them
Do not delete OBB folders by hand — the app needs them to run, and removing them usually forces a multi-gigabyte re-download or breaks the game. The clean way to reclaim the space is to uninstall the app, which removes its OBB and data folders with it.
If a game is taking too much room, check its size in Settings > Apps > [app] > Storage. Clearing cache there is safe; clearing data or uninstalling is what actually removes the OBB files.