Local Time Machine snapshots explained
When Time Machine is on, macOS also keeps snapshots on your startup disk, not only on the backup disk. They let you get files back while the backup disk is not connected.
What macOS does
According to Apple's documentation, Time Machine saves a snapshot about once an hour and keeps them for 24 hours. It also keeps a snapshot of the last successful backup while space allows. Local snapshots exist only on APFS volumes. When space runs low, macOS deletes them itself.
Why they seem to take so much space
A snapshot holds on to the blocks that existed at its time. If you then delete a big file, its space is only freed once no snapshot contains it anymore. That is why emptying the Trash sometimes changes little at first. macOS usually counts this space as “purgeable”, space it frees on its own when needed. macOS does not show the size of a single snapshot in Storage settings.
List snapshots
tmutil listlocalsnapshots /
tmutil listlocalsnapshotdates /The first command shows the names, the second only the dates, such as 2026-11-04-101500.
Delete snapshots
Usually you do not need to, because macOS removes them itself. If you need the space right away, for a large update for example:
sudo tmutil deletelocalsnapshots 2026-11-04-101500Deleted snapshots cannot be restored. Your backups on the Time Machine disk are not affected.
Where Searoom helps
Searoom lists local snapshots as their own item in System Data, with count and dates. The size says “not disclosed”, because macOS does not tell it and a guess would not be honest. “Delete Snapshots…” tells you first that this cannot be undone, asks for your administrator password, and afterwards shows the space that was measured as freed.
Searoom explains every storage item on your Mac in one sentence, only moves things to the Trash, removes apps with their leftovers and keeps your apps updated. 14 days with everything, then a free version stays, Pro is €29 once.
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