Mac storage basics · macOS updates and installers

What should I do when a macOS update says there isn't enough free space?

Short answer: Free more room than the download size — empty the Trash, delete old downloads and installers, restart to release temporary space, then try again.

Updates need room both to download and to unpack and install, so the free space required is well above the download size. When Software Update says there isn't enough:

  1. Empty the Trash and delete large downloads and installers you've already used.
  2. Restart — macOS often releases temporary space and old local snapshots on a restart.
  3. Check System Settings → General → Storage for quick wins such as old iPhone backups.
  4. Try the update again.

If free space doesn't rise after deleting files, snapshots are probably holding it — see why deleting doesn't free space. How much to aim for: space for a macOS update.

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