A 243 KB freeware classic that maps disk usage as a sunburst chart - no installation, no fuss
Scanner by Steffen Gerlach is a piece of freeware history: a 243 KB single file that draws your entire drive as a sunburst chart, with every directory level visible at once. No installation, no account, no background service - download, run, see.
The concentric rings show folders and files sized by the space they take, from the drive root outward. Hover a segment to see its path and size, click to zoom into a branch. It scans local drives, external disks and network paths.
Version 2.13 dates from July 2012, and the interface shows it. Yet it still runs on Windows 11, which tells you something about how little it asks from the system. Development has long stopped, so what you download is what you get.
For a USB toolkit, an old laptop, or anyone who wants the answer to "what fills this drive?" in a quarter of a megabyte.
We list it in our roundup of the 10 Best Free Disk Space Analyzers for Windows 11.
One chart shows every directory level at once, with each folder sized by the space it takes.
243 KB, no installation. Run it from a USB stick and point it at any drive.
Hover to see paths and sizes, click to zoom into a branch, and clean up from the same window.
Yes. Version 2.13 dates from 2012 and looks it, but it still runs on Windows 11 and answers the core question instantly.
Only from the author's freeware page at steffengerlach.de. Third-party download sites often wrap popular freeware in unwanted installers.