Is it safe to delete Time Machine local snapshots on a Mac?

By Mohit Nippanikar, who makes SiftMac

1. What local snapshots are

Your Time Machine drive isn’t always plugged in, so Time Machine also keeps some backups on the Mac itself. These are local snapshots, and they let you restore a file from the last day even while the backup drive is in a drawer. According to Apple:

• Time Machine saves one snapshot of your startup disk about every hour, and keeps it for 24 hours.
• It keeps one more, of your last successful Time Machine backup, until the space is needed.
• It saves another before installing any macOS update.

2. Why they don’t really fill your disk

A snapshot only holds what changed since it was taken, so most of the time it’s small. When it isn’t, macOS still counts the space as available: it doesn’t get in the way of downloading, copying or installing. Time Machine only keeps snapshots on disks with plenty of free space, and it deletes them as they age or as space is needed.

That’s why Finder’s Get Info (select Macintosh HD, then File › Get Info) can show more “Available” than the storage bar suggests: the difference is purgeable space, and snapshots are part of it, together with things like iCloud files macOS can download again.

3. When deleting them is worth it

• An installer or app refuses to start because it sees too little free space. Some check free space without counting purgeable space.
• You’ve just deleted a lot of big files and need the space back right now, not when macOS gets round to it. Files you delete stay inside the snapshots until those go.
• You’re about to do something that writes a lot, like a large video export, and want to start from a clean slate.

What you give up: restoring files from the last day while the backup drive isn’t connected, and the snapshot taken before the last macOS update. Your Time Machine backups themselves are untouched.

4. See them

In Terminal (Applications › Utilities):

tmutil listlocalsnapshots /

Each line is one snapshot, named after the moment it was taken, for example com.apple.TimeMachine.2026-11-11-101500.local. No lines means there are none.

5. Delete them the Apple way

Apple’s method is to pause automatic backups for a few minutes, which makes macOS remove the local snapshots:

1. Choose Apple menu › System Settings › General › Time Machine.
2. Click Options, set Backup Frequency to Manually, and click Done.
3. Wait a few minutes.
4. Set Backup Frequency back to automatic. Time Machine remembers your backup disks.

On macOS Monterey and earlier, deselect “Back Up Automatically” in Time Machine preferences instead, then select it again.

6. Or in Terminal

To delete every local snapshot of the startup disk at once:

sudo tmutil deletelocalsnapshots /

To delete just one, give its date and time from the list in step 4:

sudo tmutil deletelocalsnapshots 2026-11-11-101500

Or ask macOS to thin them until a given amount is free, here about 20 GB, at the highest urgency:

tmutil thinlocalsnapshots / 20000000000 4

Either way, the backups on your Time Machine drive aren’t affected.

Questions

Will deleting local snapshots delete my Time Machine backups?

No. The backups on your Time Machine disk stay as they are. Only the copies kept on the Mac itself go.

Why do they keep coming back?

That’s by design: a new snapshot about every hour while automatic backups are on, each kept for a day. They come back however you delete them.

Can I turn local snapshots off?

Not on their own. They come with automatic Time Machine backups, and switching those to manual also stops your regular backups. It’s better to leave them on and let macOS manage the space.

Are snapshots why my “System Data” is huge?

They can be part of it, but rarely the part that matters, since macOS gives that space back by itself. What else is inside System Data, and what you can clear.