Diskzy vs OmniDiskSweeper: an honest comparison
OmniDiskSweeper from The Omni Group is a free utility with one clear job: it shows the files on your drive from largest to smallest and lets you open them or move them to the Trash. It has been freeware since 2009, and Omni still offers downloads for older macOS versions as well as the current one.
Diskzy starts from the same question, what is using the space, and goes further. It names the parts of System Data, suggests what is safe to clean with a reason for each item, removes apps with their leftovers, and keeps its picture of the disk current after the first read. It is a paid app and needs macOS 15 or later.
| Diskzy | OmniDiskSweeper | |
|---|---|---|
| Price | Free for 72 hours with everything unlocked, then $9 once for 2 Macs. | Free. |
| How it shows the disk | Maps the whole disk, with search by name, kind, size or age. | A list of files and folders sorted from largest to smallest. |
| System Data | Breaks System Data into named parts, each sized and marked Safe to clear, Look first or Managed by macOS. | Not stated |
| Cleanup suggestions | Clean up tab lists caches, logs, Xcode leftovers, build folders and more, each ticked or unticked with a reason. | None. You decide what to remove from the list. |
| App uninstaller | Yes, with leftovers. | Not stated |
| Staying current after the first scan | Stays current as files change. | Not stated |
| Where deleted files go | The Trash. | The Trash. |
| Requirements | macOS 15 Sequoia or later, Apple silicon and Intel. | Not stated for the current version. Older builds are offered for macOS versions back to 10.4. |
When OmniDiskSweeper is the better choice
Choose OmniDiskSweeper if you want a free, simple list of your largest files and are comfortable judging for yourself what is safe to delete, or if you need a build for an older Mac.
When Diskzy is the better choice
Choose Diskzy if you want guidance on what is safe to clear, an explanation of System Data, an uninstaller, and a view that stays up to date without rescanning.
Details about OmniDiskSweeper were checked on October 10, 2026 against omnigroup.com, omnigroup.com. Prices and features change; check their site for the latest.
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See where your Mac's space went
Diskzy maps your disk, explains System Data and clears what's safe. Free for 72 hours, then $9 once for 2 Macs.
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