Time Machine local snapshots eating disk space
APFS local snapshots are copy-on-write images made by Time Machine and by system updates. They can take tens of gigabytes and must be managed with tmutil, never by deleting files by hand. Broza uses tmutil for this and never touches update snapshots.
What it is
Point-in-time images of a volume kept on the volume itself. Time Machine takes one every hour when it cannot reach its backup disk, and macOS takes one before it installs an update.
What it is for
They are what "enter Time Machine" browses when the backup disk is not attached, and what lets a failed update roll back. They are also why a Mac reports gigabytes of "purgeable" space: macOS deletes snapshots itself when the disk fills.
Is it safe to delete?
The Time Machine ones, yes, and only through tmutil, which is what Broza uses. macOS reports no size for a snapshot, so Broza lists them by name and never claims a number it cannot measure. Update snapshots (com.apple.os.update-*) are never proposed: a pending update needs them.
How Broza removes them
Yes, through tmutil, and only after you confirm. macOS does not report per-snapshot sizes, so Broza lists them without a size estimate. Update snapshots are never proposed.
Deleting a snapshot cannot be undone, so Broza shows a detailed summary flagged irreversible and asks for an explicit confirmation before it runs tmutil.
Check it on your Mac
Broza is a free, open-source command-line tool. Every command below is read-only except clean, and clean is a dry run until you add --apply.
broza explain snapshots broza suggest --category snapshots broza clean --category snapshotsNot installed yet? Install Broza with Homebrew, the installer script, or Cargo.