Which fits your needs?
Disk Graph: People who want saved storage history or a companion on iPhone/iPad.
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 | Disk Graph | NullDisk |
|---|---|---|
| Best fit | People who want saved storage history or a companion on iPhone/iPad. | Mac users managing local/remote storage, and developers who need Git-aware cleanup or scriptable disk reports. |
| Visualization | Radial pie chart, treemap, and snapshot sequences | Radial map, treemap, and file list; CLI terminal treemap |
| Platforms and requirements | macOS, iOS, iPadOS | Mac app: macOS 14+; CLI: macOS, Linux, Windows |
| Pricing and editions | Commercial app; check current developer and App Store purchase options. | 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 | Preview, reveal, or move selected items to the bin. | Review source and action: local Trash, explicit permanent removal, or backup/delete; remote and cloud actions depend on the destination. |
| Reports and portability | Export a snapshot and keep it: the developer documents JSON/TSV records that can be viewed in a text editor. NullDisk does not import these snapshots. | CLI produces JSON/NDJSON scan reports. Third-party scan files are not directly imported into the Mac GUI. |
Disk Graph: what stands out
A good fit for people who want saved storage history or a companion on iPhone/iPad.
Disk Graph: strengths
- Switch between radial charts and treemaps
- Logical size, allocated size, or file-count modes
- Export snapshots and animate changes across a sequence
Considerations
- Mobile scans cover locations accessible through Files
- Snapshots record inventory, not backed-up file contents
- Historical snapshots need a fresh scan before cleanup
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 Disk Graph?
A good fit for people who want saved storage history or a companion on iPhone/iPad. Commercial app; check current developer and App Store purchase options.
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.