Samsung Galaxy S21+ storage is full or the device cannot install updates

The checks in more detail

Social and streaming apps keep the most. Then use My Files, Analyze storage, which lists large files, duplicates and unused apps for removal in a few taps. Photos and videos come next. Back them up to Google Photos or OneDrive, confirm that the backup finished, and use the Free up space option to remove local copies. Empty the Trash in Gallery. Videos recorded in 8K or 4K at high frame rates take enormous space: the S21 series could shoot 8K, so old clips may be huge. Sort the Videos list by size and move the large ones to a computer or the cloud.

Check chat apps, which quietly save every photo and video that arrives, and use their storage managers to clear old media. Apps and updates need room too. The phone may need several gigabytes free for a software update, so uninstall apps you no longer use and use Archive in the Play Store. Remove offline downloads, maps and games you have finished. Restart the phone after clearing, since the figures take time to refresh. If you are always short, a USB-C drive can hold files through My Files, and a cloud plan keeps photos without filling the phone. Back up before deleting anything you cannot replace, and keep at least a tenth of the storage free.

If the number stays wrong after clearing and a restart, contact Samsung. On the S21+ the biggest hidden space users are often the Samsung apps that came with the phone, such as Samsung Health, Notes and Samsung Internet, which keep their data, and the Galaxy Store updates. Open Settings, Apps, sort by size and see whether any Samsung app is surprisingly large. Samsung Notes keeps handwritten pages and voice recordings that grow, and the camera's pro video mode saves raw data. Android 'System' use can also include the Digital Wellbeing data and keyboards' dictionaries, which a restart and clearing the keyboard's cache reduces.