Help · Mac storage

Not enough space to update macOS?

By Grant and Brad, who make Pangalin's apps · Updated 11 October 2026

macOS updates need room to download, unpack and install, and the amount varies by update and Mac. Apple doesn't publish one figure. If Software Update says there isn't enough space, this is the order to work through. Stop as soon as it has enough.

Back up first. A Time Machine backup before a macOS update is wise anyway, and it means anything you delete below is still safe.

Quick wins (5 minutes)

1. Use Software Update (System Settings › General › Software Update). Apple says it needs less space than other ways of installing.
2. Empty the Trash. Space only comes back once it's emptied. This is permanent.
3. Clear out Downloads. Old installers (.dmg, .pkg, .zip) are usually safe to remove.
4. Restart. It clears temporary files. Apple also notes that starting in safe mode clears some system caches, which can free enough room temporarily for an update.
5. Let a Time Machine backup finish with the drive connected. Local snapshots then take less room; see local snapshots.

Bigger wins (30 minutes)

6. Delete old iPhone and iPad backups you no longer need: how.
7. Remove apps you don't use, especially large ones like games, old Xcode versions and virtual machines: how to uninstall completely.
8. Find your biggest files and move or delete what you recognise: how to find large files.
9. Move big libraries to an external drive, such as Photos or old projects: how.
10. In Mail, choose Mailbox › Erase Deleted Items and Mailbox › Erase Junk Mail.

Still not enough?

Apple suggests installing from macOS Recovery as another route. If an update fails part-way, see Apple's article on errors while updating or installing macOS. After a successful update, free space can look lower for a day or two while things settle: see lost storage after a macOS update.