Disk Inventory X alternative: Peekaboo vs Disk Inventory X
By Vishva Variya · Updated
Disk Inventory X taught a lot of Mac users what a treemap is: every file a block sized by the space it takes, coloured by type. It’s free and open source under the GPL. Its latest release, 1.3, came out on December 8, 2019, and its site lists macOS 10.13 to 10.15; the release notes say it isn’t signed or notarized by Apple, so macOS warns on first launch. If you’re looking for something that’s made for the macOS you run today, here’s how Peekaboo compares.
Looking for Disk Inventory X itself? It’s at www.derlien.com.
- Disk Inventory X price
- Free (GPL, donations welcome)
- Disk Inventory X requires
- macOS 10.13 to 10.15 (version 1.3) or later
- Peekaboo
- $24.99 one-time (launch price $9.99 until Nov 9), 14-day trial, macOS 14+
Disk Inventory X figures from derlien.com (home, downloads and release notes), verified 2026-11-02.
Why pick Peekaboo over Disk Inventory X?
Built for macOS 14 and later
Peekaboo is a native app for macOS 14 Sonoma and later, on Apple silicon and Intel, signed and notarized by Apple.
A map you can drill into
Space Map is a sunburst rather than a treemap: rings of categories and folders, sized by space, that you click to drill down. Disk Usage gives the same information as a list sorted by size.
From finding to clearing
Duplicates, App Caches and the App Uninstaller turn what the map shows into something you can clear, and every cleanup goes to the Trash as a session you can put back in one click.
Peekaboo vs Disk Inventory X, job by job
| Job | Disk Inventory X | Peekaboo |
|---|---|---|
| Seeing what fills the disk | Treemap coloured by file type | Space Map sunburst and Disk Usage by folder size |
| Removing something | Move to Trash from the view | To the Trash, with the whole cleanup restorable in one click |
| Duplicates, caches, app leftovers | Not offered | Duplicates, App Caches and App Uninstaller |
| macOS supported | 10.13 to 10.15 (version 1.3, December 2019) | macOS 14 Sonoma or later |
| Price | Free, GPL | One-time per Mac after a 14-day trial |
The honest verdict
On a Mac still running macOS 10.13 to 10.15, Disk Inventory X is free and does the job, and Peekaboo won’t install there at all. On a current Mac, Peekaboo is the paid option with duplicates and undo; if you just want a free treemap that’s still maintained, GrandPerspective 3.8.1 supports macOS 14 and later.
Disk Inventory X vs Peekaboo: questions
Does Disk Inventory X work on current macOS?
- Its site lists version 1.3 for macOS 10.13 to 10.15, released December 8, 2019, with no newer release or Apple silicon build listed, as of November 2, 2026.
Why does macOS warn when I open Disk Inventory X?
- Its 1.3 release notes say the app is still not signed or notarized by Apple, so macOS shows a warning the first time; the notes suggest choosing Open from the menu.
Is there a free alternative to Disk Inventory X?
- GrandPerspective is free from SourceForge and its current version supports macOS 14 and later. Peekaboo is paid, after a 14-day free trial.