How to delete Time Machine local snapshots on a Mac

Guide · 5 min read · By Kapil Upadhyay at Logicspark · Published 8 November 2026

When Time Machine is switched on, macOS keeps local snapshots on the internal disk as well as backing up to your external drive. They let you restore a file while the backup disk is unplugged. They are counted inside System Data and, because macOS can drop them whenever it needs room, inside purgeable space too. That is why the “System Data” bar in Settings can be tens of gigabytes larger the day after a big file shuffle.

Step 1 — See whether you have any

tmutil listlocalsnapshots /

Each line is one snapshot, named with the date and time it was taken, for example com.apple.TimeMachine.2026-11-08-101500.local. To list only the dates, which is the form the delete command wants:

tmutil listlocalsnapshotdates /

On a 512 GB MacBook Pro (Mac16,8, 24 GB memory) running macOS 26.5.1, measured on 8 November 2026, the first command printed only the header Snapshots for disk /: and nothing beneath it — no local snapshots at all, because Time Machine was not set to back up automatically. If your list is empty too, snapshots are not what is filling your disk; go to the full System Data guide instead.

Step 2 — Delete one snapshot, or all of them

Delete a single snapshot by its date:

sudo tmutil deletelocalsnapshots 2026-11-08-101500

Delete every local snapshot on the startup disk at once — the tmutil manual page documents that passing a mount point instead of a date removes all of them on that disk:

sudo tmutil deletelocalsnapshots /

Run tmutil listlocalsnapshots / again afterwards to confirm the list is empty, then check the free space with df -h /System/Volumes/Data. Snapshots share blocks with your live files, so the space returned is only what the snapshots alone were holding; it can be anything from nothing to many gigabytes.

Step 3 (alternative) — Thin instead of delete

If you only need a specific amount back, ask macOS to thin snapshots until it has reclaimed that much. The amount is in bytes and the last number is the urgency, from 1 to 4:

# ask for 20 GB back, at the highest urgency
sudo tmutil thinlocalsnapshots / 20000000000 4

This is the same mechanism macOS uses on its own when a write needs room, so it never removes anything Time Machine still depends on.

Is it safe?

Yes. Local snapshots are a convenience copy. Your real backups live on the external Time Machine disk or network volume, and deletelocalsnapshots never touches those. What you lose is the ability to restore an older version of a file while that disk is disconnected. macOS keeps a local snapshot for 24 hours and also takes one before installing a software update, so expect a few to reappear.

Stopping them from coming back

Local snapshots are made because automatic Time Machine backups are on. Turning automatic backups off in System Settings › General › Time Machine stops new ones, but it also stops your backups, and that is a bad trade on a machine with anything worth keeping. Leave Time Machine on and let macOS thin the snapshots when it needs the room. Delete them by hand only when you need the space now, for example to fit a large macOS update.

Common questions

Are Time Machine local snapshots part of System Data?

Yes. macOS counts local snapshots under System Data in Storage settings, and also reports them as purgeable because it can delete them on its own when it needs room.

Does deleting local snapshots delete my Time Machine backups?

No. tmutil deletelocalsnapshots only removes the copies kept on the internal disk. Backups on your external Time Machine drive or network volume are not touched.

How do I delete all local snapshots at once?

Run sudo tmutil deletelocalsnapshots / in Terminal. Passing the mount point instead of a date removes every local Time Machine snapshot on that disk.

Why do local snapshots keep coming back?

Time Machine creates them while automatic backups are switched on, and macOS also takes one before a software update. Each is kept for about 24 hours or until space is needed.