How to delete Time Machine local snapshots on a Mac

Time Machine local snapshots can fill System Data. How to list them with tmutil, delete one or all of them safely, use Disk Utility instead, and what happens to your backups.

What local snapshots are

When Time Machine is on, macOS saves snapshots of your startup disk on the Mac itself, so you can get an older version of a file back even when the backup disk isn't connected. macOS updates make snapshots too, so an update can be undone. They're meant to be deleted on their own after a while or when space runs short, which is why the Finder sometimes shows more free space than Storage settings. In practice they often linger, and Storage settings counts them as System Data.

Is it safe to delete them?

Yes. Deleting a local snapshot doesn't touch the backups on your Time Machine disk or any of your files. You only lose the ability to restore from that particular on-Mac snapshot.

List them

Open Terminal (Applications › Utilities) and run:

tmutil listlocalsnapshots /

Each line is one snapshot, with its date in the name, for example com.apple.TimeMachine.2026-11-10-093015.local. No lines means there are none, and your System Data is something else.

Delete one

Use the date part of its name. macOS asks for your password.

sudo tmutil deletelocalsnapshots 2026-11-10-093015

Delete all of them on the startup disk

sudo tmutil deletelocalsnapshots /

Run the list command again to check. Storage settings can take a few minutes to catch up.

Or use Disk Utility

Open Disk Utility and choose View › Show APFS Snapshots.
Select your startup disk's data volume. The snapshots are listed at the bottom with their size.
Select one and click − (or right-click › Delete).

If they keep coming back

That's normal while Time Machine is on: it makes a new one every hour and keeps them for about a day. If they pile up instead of going away, back up to your Time Machine disk so macOS can let go of them, then delete the leftovers as above.