How to Delete Local Time Machine Snapshots on a Mac

In short: Wondering why System Data eats so much of your Mac's disk? Local Time Machine snapshots are a common culprit. Here's how to see them and clear them safely with tmutil, plus a calmer way to keep an eye on storage over time.

If you open Apple menu > System Settings > General > Storage and see a huge, mysterious slab labeled System Data, local Time Machine snapshots are one of the most common reasons. macOS quietly keeps these on-disk copies of your backups so it can restore recent versions even when your backup drive is unplugged. That's a genuinely useful safety feature, but the snapshots can balloon to tens of gigabytes and make your Mac feel low on space. This guide shows you how to delete local Time Machine snapshots on a Mac using tmutil, the built-in command-line tool, on macOS Sonoma and Sequoia (14 and 15).

What local snapshots actually are

When Time Machine is turned on, macOS periodically creates local snapshots on your startup disk between full backups. They live in the APFS file system rather than in a folder you can browse, which is why they don't show up in Finder and can feel invisible. macOS is supposed to purge them automatically when you run low on space or once they're 24 hours old, but that cleanup is not always timely, and after a big update or a large file operation you can be left with more snapshots than you expected.

The good news is that removing a local snapshot does not touch your real files or your off-disk Time Machine backups. You're only clearing the temporary on-disk copies, and Time Machine will make fresh ones on its normal schedule.

See your snapshots before you delete anything

Open Terminal (in Applications > Utilities) and run this to list the local snapshots on your system volume:

tmutil listlocalsnapshots /

You'll see entries with timestamps in their names, like com.apple.TimeMachine.2025-01-14-093000.local. If nothing is listed, you have no local snapshots and System Data is bloated for some other reason. If you do see entries, the date stamps tell you how old each one is. Looking first is the whole point: you're previewing exactly what exists before you change anything, so there are no surprises.

Delete local Time Machine snapshots with tmutil

The simplest, Apple-sanctioned approach is to let macOS reclaim snapshot space by a target amount. This command asks the system to thin snapshots on the startup volume until it frees roughly the number of gigabytes you request (the last number is a purge-urgency level, where 4 is the most aggressive):

tmutil thinlocalsnapshots / 21474836480 4

That example targets about 20 GB. Adjust the byte count for how much you want back. If you'd rather remove a specific snapshot you saw in the list, delete it by its timestamp:

tmutil deletelocalsnapshots 2025-01-14-093000

Run tmutil listlocalsnapshots / again afterward to confirm the ones you targeted are gone. Storage in System Settings can take a minute or two to catch up, so don't worry if the number doesn't drop the instant the command finishes.

A gentler alternative without the Terminal

If you'd rather not use commands at all, you can simply turn Time Machine off for a short while: go to System Settings > General > Time Machine, remove or pause the backup destination, and macOS will start aging out local snapshots on its own. Turn it back on once space has recovered. This is slower than tmutil but requires no typing, and it's a fine choice if the Terminal makes you nervous.

Keep it reversible, and keep it private

A quick safety reminder: local snapshots aren't in the Trash, so tmutil removes them directly rather than moving them to a recoverable bin. That's expected for this one macOS feature. But it's a good rule of thumb for everything else you clean on a Mac. Whenever you're clearing caches, logs, or leftover files, prefer tools that preview first, touch only user-level junk by default, and send removals to the Trash so a mistake is reversible with a single drag back out. Permanent deletion should be a deliberate choice, never the default.

Privacy is worth a thought too. A disk cleaner has no legitimate reason to phone home, and you can verify that yourself with a firewall like Little Snitch and watch whether an app makes surprise outbound connections while it scans.

If you want a companion app for the routine cleanup that doesn't require the command line, two honest picks fit the safe approach above. CoreSweep is our top free pick: free forever, an optional one-time Pro at $49 with no subscription, zero telemetry, and deletes that go to the Trash so they stay reversible. SkoonMac is the best-value runner-up, also free with a one-time $19 Pro. Either one previews before it acts, which is exactly the habit that keeps disk cleaning safe.

Quick recap

List your snapshots with tmutil listlocalsnapshots /, reclaim space with tmutil thinlocalsnapshots or remove a specific one with tmutil deletelocalsnapshots, and give Storage a moment to update. Your files and your real backups are untouched, and Time Machine will resume making fresh snapshots on its own. That's all it takes to shrink a stubborn System Data figure back down to something reasonable.

Frequently asked questions

Is it safe to delete local Time Machine snapshots?

Yes. Local snapshots are only temporary on-disk copies macOS keeps between full backups, so removing them does not touch your real files or your off-disk Time Machine backups. Time Machine simply makes fresh snapshots on its normal schedule afterward.

Why is my Mac's System Data so large?

Local Time Machine snapshots are one of the most common reasons. macOS stores them in the APFS file system rather than in a Finder folder, so they stay invisible while they quietly grow to tens of gigabytes. macOS is supposed to purge them automatically, but that cleanup is not always timely, especially after a big update or a large file operation.

Can I delete local snapshots without using Terminal?

Yes. Go to System Settings > General > Time Machine and remove or pause the backup destination, and macOS will start aging out local snapshots on its own. Turn Time Machine back on once space has recovered. It is slower than tmutil but requires no typing.

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