How to delete Time Machine local snapshots on a Mac

Q: Will local snapshots come back after I delete them?

Yes, that is normal. The moment Time Machine runs its next backup, macOS will start creating new local snapshots again. They are meant to grow and shrink over time.

Q: What is the difference between tmutil thinlocalsnapshots and tmutil deletelocalsnapshots?

thinlocalsnapshots asks macOS to reclaim a target amount of space by trimming older snapshots — it is gentler and lets the system decide what to remove. deletelocalsnapshots removes one specific snapshot by its date stamp. For most people, thinlocalsnapshots or the GUI method is the safer choice.

Hidden space · 7 min read · Updated June 2026

You open About This Mac, glance at your storage bar, and notice a huge chunk labelled System Data — or a mysterious block of "other" eating dozens of gigabytes. One common culprit is Time Machine local snapshots. They build up quietly in the background, and most people have never heard of them.

This guide explains what local snapshots are, why they pile up, and the safest ways to delete them or let macOS handle them for you.

What are Time Machine local snapshots?

Time Machine is Apple's built-in backup tool. It saves copies of your files to an external hard drive or a network drive. That part most people know.

What is less well-known is that Time Machine also saves small copies of your files directly on your Mac's internal disk. These are called local snapshots. Think of them as quick, on-device checkpoints. If you accidentally delete a document and your backup drive is not nearby, you can still go back in time and recover it from a local snapshot.

macOS creates these roughly every hour. It keeps snapshots from roughly the last 24 hours plus one snapshot from your last successful backup to the external drive. The moment your Mac needs more room, macOS automatically purges the oldest snapshots to make space.

Local snapshots live on Apple's modern file system, called APFS (Apple File System). APFS snapshots are very space-efficient — they only store the differences from the previous state, not whole new copies of every file. Even so, on a small or nearly-full drive, they can add up to 10, 20, or even 30+ gigabytes.

Why do local snapshots take up so much space?

A few reasons:

Your backup drive has not been connected in a while. Every hour you are away from your external drive, another snapshot piles up.
You work with large files. Video projects, virtual machine files, and photo libraries create bigger snapshot deltas.
macOS has not needed the room yet. The purge is automatic, but it only happens when another app actually requests space. If your drive is at 60% full, macOS might keep months of snapshots happily sitting there.

Because macOS considers these snapshots "removable on demand," they are counted as purgeable space. That means they show up in the storage meter but macOS does not panic about them. They also inflate the System Data figure you see in storage settings.

Key point: Deleting local snapshots only removes backup history stored on your internal disk. It does not delete any of your real files. Your backups on your external Time Machine drive are completely unaffected.

How to check if local snapshots are taking up space

Before you do anything, it helps to see what you are dealing with.

Option 1 — Check in Terminal (list all snapshots)

Open Terminal (search for it in Spotlight — press Cmd + Space and type "Terminal"). Then run:

tmutil listlocalsnapshots /

You will see a list of entries that look like this:

com.apple.TimeMachine.2026-06-21-101500.local
com.apple.TimeMachine.2026-06-20-221300.local
com.apple.TimeMachine.2026-06-20-141000.local

Each line is one snapshot, named by the date and time it was taken. A long list means many snapshots have built up.

Option 2 — Check in Disk Utility (visual view)

Open Disk Utility (again, Spotlight is easiest). Select your main volume — usually called "Macintosh HD". Then go to the menu bar: View → Show APFS Snapshots. You will see each APFS snapshot listed.

You can also list them in Terminal with:

diskutil apfs listSnapshots /

How to delete Time Machine local snapshots

There are three approaches, from safest to most direct.

Method 1 — The GUI path: turn off automatic backups temporarily (safest)

This is the best option for most people. No Terminal needed.

Open System Settings (the gear icon in your Dock or Apple menu).
Go to General → Time Machine.
Turn off "Back Up Automatically."
Wait a few minutes. macOS knows backups are off and will begin releasing local snapshots on its own.
When you reconnect your backup drive and turn automatic backups back on, Time Machine will resume normally and snapshots will start rebuilding — that is completely normal.

On older versions of macOS, look for the Time Machine icon in the menu bar at the top of your screen, click it, and choose "Open Time Machine Preferences" to find the same toggle.

Method 2 — Ask macOS to thin snapshots (Terminal, gentle)

Thinning means you ask macOS to reclaim a target amount of space by trimming older snapshots. It is gentler than deleting one by one — macOS decides what to remove.

tmutil thinlocalsnapshots / 21000000000 4

Breaking that down:

/ — the volume to thin (your main disk)
21000000000 — the amount of space to try to free, in bytes (this example asks for about 21 GB)
4 — urgency level, from 1 (gentle) to 4 (aggressive). A 4 means "really try hard to free that space."

Change the number of bytes to whatever you want to reclaim. 10 GB = 10000000000, 5 GB = 5000000000, and so on.

Method 3 — Delete one specific snapshot by date (Terminal, precise)

If you want to remove a single snapshot by its exact date stamp, use deletelocalsnapshots. Note that this command needs sudo — that means administrator permission, and your Mac will ask for your login password.

sudo tmutil deletelocalsnapshots 2026-06-21-101500

Replace 2026-06-21-101500 with the actual date stamp from the list you got in the previous step. Type your password when prompted — the cursor will not move, but macOS is listening.

Repeat for each snapshot you want to remove.

See all your local snapshots in one place — no Terminal needed.

Storage Bee's snapshot view lists every local Time Machine snapshot, shows how much space each one is using, and lets you remove them safely — no commands required.

⬇︎ Download Storage Bee

What happens after you delete local snapshots?

A few things to expect:

Your files are fine. Nothing you are currently working on is affected. Local snapshots are backup history, not your active files.
The space might not look freed immediately. macOS can take a few minutes to update the storage meter after snapshots are removed.
Snapshots will come back. The next time Time Machine runs a backup, it starts creating local snapshots again. This is normal and expected behaviour. If you find them piling up again, it usually means your backup drive is not being connected regularly enough.
Your external backups are untouched. Everything on your Time Machine drive stays exactly as it was.

If you are seeing a not enough space to install an update message, clearing local snapshots is one of the first things worth trying — they are purgeable, so macOS should handle it automatically, but sometimes a manual nudge helps.

How Storage Bee helps you manage snapshots

Typing Terminal commands is fine if you are comfortable with it. But if you would rather see a clear picture without any command line work, Storage Bee's dedicated Time Machine / snapshots view is built for exactly this situation.

Storage Bee is a Mac storage management app. It shows you a breakdown of what is taking up room on your disk — including local snapshots — so you can make informed decisions about what to remove. The snapshots view:

Lists all local Time Machine snapshots on your disk
Estimates how much space each one is using
Lets you remove snapshots without opening Terminal
Moves items to the Trash where applicable, so the action is reversible

Everything Storage Bee does stays local and private on your Mac. If you are curious why your Mac is full, the snapshot view is a great place to start looking.

Frequently asked questions

Is it safe to delete Time Machine local snapshots?

Yes. Deleting local snapshots only removes backup history stored on your internal disk. It does not touch your current files. Your backups on your external Time Machine drive are completely unaffected. The worst that can happen is that you lose the ability to go back to a file version from the last day or so via Time Machine — but only if that version lived solely in a local snapshot.

Will local snapshots come back after I delete them?

Yes, and that is normal. The moment Time Machine runs its next backup, macOS will start creating new local snapshots again. They are designed to grow and shrink over time. If you want to stop them from building up, keep your backup drive connected regularly or turn off automatic backups in System Settings → General → Time Machine.

Why do local snapshots show up as System Data or purgeable space?

macOS counts local snapshots as purgeable space because it can delete them automatically when another app needs the room. Storage tools and About This Mac often lump them into the System Data category, which is why that number can look surprisingly large — sometimes 20 GB or more on a Mac that has been running for a while without connecting its backup drive.

What is the difference between tmutil thinlocalsnapshots and tmutil deletelocalsnapshots?

thinlocalsnapshots asks macOS to reclaim a target amount of space by trimming older snapshots — it is gentler and lets the system decide what to remove. deletelocalsnapshots removes one specific snapshot by its exact date stamp. For most people, thinlocalsnapshots or the GUI method (turning off automatic backups in System Settings) is the safer choice, since you are not manually picking individual files to erase.

← Back to the blog