Which fits your needs?
DissectMac: People who want free inspection and optional paid app/leftover cleanup.
NullDisk: Mac users managing local/remote storage, and developers who need Git-aware cleanup or scriptable disk reports.
Features, pricing, and workflow
Scroll across to compare
| Feature | DissectMac | NullDisk |
|---|---|---|
| Best fit | People who want free inspection and optional paid app/leftover cleanup. | Mac users managing local/remote storage, and developers who need Git-aware cleanup or scriptable disk reports. |
| Visualization | Treemap and search | Radial map, treemap, and file list; CLI terminal treemap |
| Platforms and requirements | macOS (Intel and Apple Silicon builds) | Mac app: macOS 14+; CLI: macOS, Linux, Windows |
| Pricing and editions | Map, search, and monitor are free; Pro is listed at $12.99 once plus tax. | Direct Mac edition free with reminders; optional $9.99 one-time personal license or team seat removes reminders. App Store terms are separate. |
| Open source | No | No |
| Native macOS UI | Yes | Yes |
| Cleanup workflow | Pro moves selected files and app leftovers to Trash after review. | Review source and action: local Trash, explicit permanent removal, or backup/delete; remote and cloud actions depend on the destination. |
| Reports and portability | The overview does not establish scan-report export. Preserve any app-removal decisions and rescan the same folders in NullDisk. | CLI produces JSON/NDJSON scan reports. Third-party scan files are not directly imported into the Mac GUI. |
DissectMac: what stands out
A good fit for people who want free inspection and optional paid app/leftover cleanup.
DissectMac: strengths
- Free map, file search, and live monitor
- Filters for developer files and large storage categories
- Pro uninstaller and app-leftover cleanup
Considerations
- In-app clearing and uninstallation require Pro
- Treemap is the documented graphical view
- Confirm suspected leftovers belong to apps you no longer need
NullDisk: what stands out
A good fit for Mac users managing local/remote storage, and developers who need Git-aware cleanup or scriptable disk reports.
NullDisk: strengths
- Radial and treemap views with local, SSH, and cloud sources
- Git-aware development cleanup for generated output and eligible worktrees
- Native Mac UI plus terminal UI and JSON/NDJSON CLI reports
Considerations
- Desktop GUI requires macOS 14+; Linux/Windows use the separate CLI
- Mac app sends anonymous usage telemetry; no in-app opt-out at this review
- No content-based duplicate finder; allocated bytes are not a guaranteed recovery total
For a useful comparison on your own drive, match the scan root, access permissions, and size mode. Chart style changes how you explore the results; it does not by itself establish measurement accuracy.
Common questions
When should I choose DissectMac?
A good fit for people who want free inspection and optional paid app/leftover cleanup. Map, search, and monitor are free; Pro is listed at $12.99 once plus tax.
When should I choose NullDisk?
A good fit for Mac users managing local/remote storage, and developers who need Git-aware cleanup or scriptable disk reports. Direct Mac edition free with reminders; optional $9.99 one-time personal license or team seat removes reminders. App Store terms are separate.
Will both apps show the same size?
Not necessarily. Match the scan root, permissions, exclusions, and logical/allocated-size mode. Hard links, APFS clones, snapshots, sparse files, and cloud placeholders can change totals. A reported size is not a guaranteed amount recovered after deletion.