WhatSize is a file system utility that allows you to quickly view and reclaim disk space.

WhatSize quickly measures the size of your hard drive and allows you to sort, filter, and refine the results. The files and folders are automatically sorted by size with the biggest sizes first.

A visual display of the contents of your hard drive that enables you to drill-down and discover how your disk space is being used.

Intelligent tools that suggest ways you can reclaim disk space. Such as unused language locales, unused binary portions from universal applications, etc.

Identifies duplicate files on your system so that you can remove them. You would be surprised at how many useless files might be laying around on your hard drive.

What’s New

Version 5.3.2

WhatSize is now compatible with Apple's GateKeeper Technology for downloads outside Mac App Store.
Addressed issuse where the file names started with '.Trash'.
Addressed rare crash when moving duplicates into the Trash.
Addressed issue of incorrect Trash icon.
Addressed incorrect size formatting when exporting as CSV.
Addressed file size calculations in Mountain Lion.
Add column sorting on TableView mode when displaying duplicates.
Optimized file path sorting by using Grand Central Dispatch.
Added FileName column on TableView mode.
Added right click "Selection Size" to display detailed information.
Addressed automatic graphics context switch to conserve battery time on laptops.

Ratings and Reviews

Skenzer ,

My favorite for what it does...

There are some other apps out there that do this type of thing and do it very well. However, this one is my favorite for finding what files and folders are taking up the most space on my drive.
I really like the fact that it offers options on how I want to view the information unlike another app that I have that limits me to viewing it in a Pie Chart style.
It's a great app and I would highly recommend it!

MtnBiker2001 ,

Just what i was looking for!

Excellent program. If you’re a pc convert like myself and looking for a program like Treesize for the pc, this is it. Found a duplicate movie on the hd right away, have no idea how i ended with two of the same one. Also has a “find duplicates” mode too. Kinda cool to see how things are structured in the mac world of hard drives. Anyway great $15 spent.

docgarner ,

Bait and Switch

Learn from my mistake. This is a version they’ve downgraded so that it can no longer scan as root. It’s a full version number and then-some behind the actual current version on their website. Once you buy this, you’ll learn that it costs an extra $15 to upgrade to the current version of the program. There are a dozen entirely free utilities that does what this version of the program does; the only prior advantage was that it could scan as root (to show hidden disk space usage) and this version absolutely does NOT do so. Save your money.


4.3 MB

OS X 10.6 or later



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.