My Mac's Disk Was Full. One Free Command Showed Me Why

Finding out what fills your Mac's disk should be easy. Every Mac has a Storage page for exactly that.

But that page only gives you categories. "Documents: 11.9 GB." Which documents? Where?

And here is what that actually looks like on my machine. One of my project folders had quietly grown to 36.6 GB. Two folders of old test runs took 35.5 GB of it. Finder made that hard to spot. A free tool called Mole put both at the top of its list.

I'm not sharing my own disk, so I rebuilt the same situation on a test Mac with sample files. Here's the whole thing in one minute:

What Mole is

Mole is a free, open-source tool for Mac (GPL-3.0, over 70,000 stars on GitHub). It runs in the Terminal, the text window every Mac already has. It needs macOS 12 or newer and works on Intel and Apple Silicon (github.com).

It can do several things. The one I use is mo analyze: a disk explorer that lists folders by size, biggest first.