When a Google TV box says storage is full, the space is usually taken by app caches, system updates and apps you never use, including ones pre-installed on the box. You can clear most of it from the Settings menu without a reset. Menu names vary by device and software version, so treat the paths as pointers.
Quick answer: Open Settings > Apps, clear the cache of your biggest apps, uninstall what you don't use, and check the storage screen again. If you still run short, a USB drive can help on devices that support it.
Where does the storage go?
- App caches. Streaming apps store thumbnails and temporary video data.
- App data and downloads. Offline downloads and player databases can grow large.
- System and app updates. A pending update needs free space to install.
- Pre-installed apps. These take room even if you never open them.
Storage differs by model. The Google TV Streamer has 32 GB, and the 2026 onn 4K Pro is listed with 32 GB (see Google TV devices compared). Older Chromecast with Google TV units have noticeably less, so they fill up sooner.
1. Check what is using space
Look for Settings > System > Storage (on some devices it is under Device Preferences). The screen shows total and free space, and often a per-app breakdown. If it doesn't, open Settings > Apps > See all apps and look at each app's details.
2. Clear caches
- Go to Settings > Apps > See all apps.
- Pick a large app, usually a streaming or browser app.
- Choose Clear cache. This is safe: it removes temporary files only.
Be careful with Clear data: it resets the app and signs you out.
3. Uninstall apps you don't use
In the same app list, choose an app and select Uninstall. Pre-installed apps may only offer Disable, which stops them running and, on many devices, frees some space.
4. Let updates finish
If updates keep failing for lack of room, free space first, then check Settings > System > About > System update and the Play Store's update list.
5. When does a USB drive help?
Some boxes accept a USB drive, which you can format as extra storage for apps on devices that support it. The onn 4K Pro has a USB 2.0 port. Support differs by model and software, and a slow drive can make apps run slowly. We could not confirm USB support for every Google TV device, so check your model before buying a drive. Move media, not system apps, to external storage where it is offered.
If that didn't work
If space stays tight, a factory reset gives a clean start, but you must set up everything again. First note your model, free and total space and the biggest apps from the storage screen. Our Android TV box buying guide covers choosing a box with enough storage next time.
Let us know your model and what turned out to be the biggest space hog.