Time Machine local snapshots are taking up space on your Mac

Why it happens

With Time Machine on, your Mac takes snapshots of your files on its own drive, roughly every hour. They let you get a file back even when the backup disk isn't plugged in. They count as purgeable space, so macOS removes them by itself when an app or update needs room.

How to fix it

1. Open the Apple menu, choose System Settings, then General, then Storage. Snapshots show up as purgeable space or inside System Data, and the bar can take a moment to add up.

   General›Storage

2. Leave them be. They're removed by themselves within about 24 hours, and straight away if something needs the space.

3. Comfortable with Terminal? Open it from Applications, then Utilities, and run the read-only command in the Terminal box below to list the snapshots on your startup disk. It only shows them and changes nothing.

   Terminal

4. Connect your Time Machine backup disk now and then. Regular backups to the disk keep your files safe whatever happens to the snapshots.

Still not fixed?

1. If your Mac says it doesn't have enough space for an update or a big file, restart it and try again. macOS frees purgeable space when it's asked for.

   General›Software Update

2. Snapshots are rarely the real space problem. Look at the biggest categories in Storage, empty the Trash, and move large files you seldom use to an external drive.

   General›Storage

3. Check your Time Machine settings are set up the way you expect, with the right backup disk listed.

   General›Time Machine

4. If snapshots older than a day stay on your Mac and keep it full even after a restart, contact Apple Support.