WhatSize alternatives, and where a one time purchase wins
WhatSize is a paid measuring tool with a trial and a fixed price. What it does well, and the free and paid options either side of it.
WhatSize belongs to an older and more honest tradition of Mac software: one purchase, one job, a trial before you pay. If you are comparing it against a subscription cleaner, it is worth being clear that these are different categories rather than different prices.
What it is good at
- Measuring, with filters. Sorting, filtering and refining a scan is its strength, and it is more flexible than a plain treemap.
- A 30 day trial. Long enough to actually decide, which is rarer than it should be.
- A one time price. $14.99 with paid upgrades between major versions is a model that ages well against a subscription.
- Broad macOS support. Big Sur through Tahoe covers machines that newer tools have dropped.
Where the differences are
| Tool | Cost | Shape | Adds |
|---|---|---|---|
| WhatSize | $14.99 one time | Sortable list, filters | Cleaning tools for logs and caches |
| DaisyDisk | $9.99 one time | Sunburst rings | Polish, and delete from the map |
| GrandPerspective | Free, or $2.99 | Treemap | Nothing beyond the map, which is the point |
| OmniDiskSweeper | No price named | Sorted list | Nothing. It lists and it deletes |
| Free Mac | Free to scan | Treemap, app and developer views | App footprints and rebuildable caches, named |
Between the paid one time options the differences are presentation and preference rather than capability. DaisyDisk is the one to compare against directly, and GrandPerspective is the free tool that does most of the same job.
The question any measuring tool leaves open
All of them tell you a folder is large. None of them tell you whether it matters. A 6 GB folder that is a browser cache and a 6 GB folder that is the only copy of a project look identical in a list sorted by size, and that distinction is where the risk in cleaning up actually lives.
That is the gap Free Mac aims at rather than the measuring itself: applications totalled with the folders they scattered, and developer output identified as rebuildable. The honest trade is that the scan and the map are free, and exact sizes, opening a folder and removing anything need a key at $19.99 every six months. For a tool you will use twice a year, a one time $14.99 is the better arithmetic and it would be silly to pretend otherwise.
Common questions
How much does WhatSize cost?
$14.99 to buy, or $9.99 as an upgrade, with a free 30 day trial, checked on 9 September 2026. The current version is 8.2.9 and it supports macOS from Big Sur 11 through Tahoe 26.
Is there a free alternative to WhatSize?
GrandPerspective is free and draws a treemap of the same data, and OmniDiskSweeper gives a sorted list at no stated price. For a single large file, a du command in Terminal does the core job with nothing installed.
What is the difference between a list and a treemap?
A list gives exact numbers and sorts precisely, which is better for deciding. A treemap shows proportion at a glance, which is better for finding. Most people find one of the two obviously easier to read, and that is a preference rather than a capability difference.
Do disk measuring tools need full disk access?
To measure everything, yes. Without it macOS blocks parts of your home folder and system locations, and any tool will silently under report. That applies equally to commands run in Terminal.