Which fits your needs?
GrandPerspective: People who want a free, inspectable treemap and reusable scan records.
WhatSize: Mac users who favor column browsing and integrated duplicate/cleanup tools.
Features, pricing, and workflow
Scroll across to compare
| Feature | GrandPerspective | WhatSize |
|---|---|---|
| Best fit | People who want a free, inspectable treemap and reusable scan records. | Mac users who favor column browsing and integrated duplicate/cleanup tools. |
| Visualization | Treemap with configurable colors and filters | Size-sorted columns and measurement views |
| Platforms and requirements | macOS 14+ (current release) | macOS 11+ (current vendor requirements) |
| Pricing and editions | Free from SourceForge; the same app is $2.99 in the US App Store. | Vendor lists $14.99 and a 30-day trial; upgrades may be priced separately. |
| Open source | Yes | No |
| Native macOS UI | Yes | Yes |
| Cleanup workflow | Delete files or folders from the view; review selection and deletion preferences. | Review the chosen cleaning or duplicate action before applying it. |
| Reports and portability | Save the scan for reopening in GrandPerspective, or export text and images. NullDisk does not import GrandPerspective scan files; retain exports and rescan the same location. | Preserve any saved measurements or reports supported by your version. The cited overview does not establish an import format shared with NullDisk. |
GrandPerspective: what stands out
A good fit for people who want a free, inspectable treemap and reusable scan records.
GrandPerspective: strengths
- Configurable colors, masks, searches, and scan exclusions
- Quick Look, Finder integration, and file/folder deletion
- Save/reload scans and export text or images
Considerations
- Treemap rather than radial navigation
- Older macOS versions require an older release
- App Store updates can follow SourceForge releases later
WhatSize: what stands out
A good fit for Mac users who favor column browsing and integrated duplicate/cleanup tools.
WhatSize: strengths
- Size-sorted columns and detailed filtering
- Duplicate-file tools and cleanup categories
- Updates measurements as the filesystem changes
Considerations
- Paid license after the trial
- Cleanup categories still require your judgment
- Check upgrade terms separately from the initial purchase
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 GrandPerspective?
A good fit for people who want a free, inspectable treemap and reusable scan records. Free from SourceForge; the same app is $2.99 in the US App Store.
When should I choose WhatSize?
A good fit for Mac users who favor column browsing and integrated duplicate/cleanup tools. Vendor lists $14.99 and a 30-day trial; upgrades may be priced separately.
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.