SquirrelDisk

Overview

SquirrelDisk is a free, open-source disk usage analyzer for Windows, macOS and Linux. It maps your whole drive as an animated sunburst chart that builds live while the scan runs, so the biggest folders surface in seconds instead of after a coffee break.

Key Functionality

Click a slice to zoom into a folder, click the center to go back. A side list always shows the largest items first, and tiny files are grouped so the chart stays readable. Prefer boxes? A treemap view is one setting away, and clicking, collecting and deleting work the same in both.

Cleanup and Duplicates

The collector is the standout idea: drag folders into it as you explore, then move the whole batch to the Trash at once - recoverable if you change your mind. Secure erase and backup-then-delete options are built in. A duplicate finder matches files by content, not by name, and shows exactly how much space each extra copy wastes.

Performance

Scans are fast and the interface stays responsive while they run. The app is written in Rust, keeps a small footprint, and can also scan servers over SSH and cloud storage.

Use Cases

For anyone who finds WinDirStat's looks stuck in another era, or who works across Windows, macOS and Linux and wants one tool everywhere.

We list it in our roundup of the 10 Best Free Disk Space Analyzers for Windows 11.