BackupEver noticed your Mac's free space doesn't add up, or found com.apple.TimeMachine snapshots listed on your startup disk? Those are local snapshots, and they're one of Time Machine's most misunderstood features.
What local snapshots are
Every time Time Machine runs, it first captures a snapshot on your Mac's own startup disk, then copies it to your backup drive. The local copy stays behind as a convenience: it lets you restore recent file versions even when your backup drive isn't connected — on a plane, away from your desk, wherever.
Three things to know:
- They're not your real backups. Your history lives on the backup drive. Local snapshots are a cache of recent restore points.
- macOS manages them automatically — they're typically cleaned up after about 24 hours, or sooner under disk pressure. The space they use is "purgeable": macOS reclaims it when something else needs room.
- Their dates mirror your backup schedule, which is why people mistake them for the backups themselves.
Is it safe to delete them?
Yes — with one caveat. Deleting local snapshots never touches your backup drive. The caveat: a snapshot that hasn't been copied to your backup drive yet (the drive was disconnected, or the backup didn't finish) is the only copy of that restore point. Delete it and that moment in time is gone for good.
The Terminal way
List them:
tmutil listlocalsnapshots /Delete one by its date stamp:
tmutil deletelocalsnapshots 2026-07-16-093000Or ask macOS to thin them down to reclaim space:
tmutil thinlocalsnapshots / 20000000000 4This works, but it's blind: nothing tells you whether a snapshot you're deleting has made it to your backup drive or not.
The easy way — with the safety information built in
BackupTempo (free) includes a Local Snapshots manager — open its Health window and click Local Snapshots… Every snapshot is listed with an honest label:
- In backups — a completed backup on your backup drive covers this restore point. Deleting it only frees space.
- Only on this Mac — this restore point hasn't reached your backups yet. Deleting it loses it permanently, and the app warns you before you do.
Delete one, or all — with confirmations that tell you exactly which case you're in. It's the same information Time Machine has all along; it just never shows you.
When deleting actually helps
Local snapshots rarely cause disk-full problems by themselves — macOS purges them under pressure. Deleting them helps most when you need a large amount of contiguous space right now (video export, VM disk, giant download) and can't wait for macOS to get around to it. If your disk is chronically full, snapshots aren't the culprit — but a too-full startup disk will eventually break Time Machine itself, which needs ~10 GB free to stage each backup.