Can it show what’s inside System Data?

The parts it can explain: app caches, developer data, local snapshots, purgeable space and the Apple Intelligence models.

Does it delete anything on its own?

No. Nothing moves until you choose, and your files go to the Trash, where Undo Cleanup can put them back.

Does it scan external drives?

Space Map and Disk Usage cover the startup disk. Network drives aren’t supported yet.

Is there a subscription?

No. Every feature is free for 14 days, then Peekaboo is a one-time purchase per Mac.

Peekaboo · Space Map

See what’s taking up space on your Mac

Storage settings gives you a coloured bar and a vague “System Data”. Space Map shows the same disk as a map you can click into, down to the folder that’s actually big.

Download free trial14 days free · macOS 14+ · Updated November 3, 2026

What it does

A map you can click: Space Map draws the disk as a sunburst by category and folder. Click any slice to drill in; the biggest things are the biggest shapes.
Every folder by size: Disk Usage lists every folder on the disk by size, so the answer to “where did 80 GB go?” is a sorted list, not a hunt.
The space macOS frees itself: Purgeable iCloud copies, caches and local snapshots are shown separately, as are the Apple Intelligence models filed under System Data.
From seeing to clearing: Send anything to the Trash straight from the map, or open Clean Up for duplicates, old downloads and unused apps. Every cleanup can be undone.

How to use it

1Open Space Map.⇧⌘M
2Click the biggest slice, and keep clicking until you find the folder.
3Move what you don’t need to the Trash, or undo it later.⌥⌘Z

When another app fits better

Space Map covers your startup disk; to map external or network drives, [DaisyDisk](/alternatives/daisydisk/) or Nektony’s [Disk Space Analyzer](/alternatives/disk-space-analyzer/) do that. If a free picture is all you want, [GrandPerspective](/alternatives/grandperspective/) draws a treemap at no cost.

Questions

Can it show what’s inside System Data?: The parts it can explain: app caches, developer data, local snapshots, purgeable space and the Apple Intelligence models.
Does it delete anything on its own?: No. Nothing moves until you choose, and your files go to the Trash, where Undo Cleanup can put them back.
Does it scan external drives?: Space Map and Disk Usage cover the startup disk. Network drives aren’t supported yet.
Is there a subscription?: No. Every feature is free for 14 days, then Peekaboo is a one-time purchase per Mac.