SpaceSniffer for Mac and Linux: a free alternative

The short answer

SpaceSniffer doesn't run on macOS or Linux. It's a Windows program, and the official site only offers a Windows download. Its source code isn't published, so there's no community port either.

If you want SpaceSniffer's idea on a Mac or a Linux PC (see your whole disk as boxes sized by space, zoom into the big ones, clean up), SquirrelDisk is a free option. It's open source, it runs on macOS, Linux and Windows, and it shows your disk as a treemap or a sunburst.

Other choices:

• Mac: GrandPerspective: free and open source, treemap view.
• Mac: DaisyDisk: paid ($9.99 one-time), sunburst view. See our DaisyDisk comparison.
• Linux: QDirStat: free and open source, treemap plus a detailed tree, in most distributions' repositories.
• Linux: Filelight (KDE) and Disk Usage Analyzer (GNOME): free, ring charts, often already installed.
• Terminal: du -sh * | sort -h on both systems, or ncdu for an interactive view.

SpaceSniffer vs SquirrelDisk

Checked on 5 October 2026 on uderzo.it and Wikipedia.

How SquirrelDisk works

Pick a drive or a folder. The chart appears straight away and fills in during the scan. The default is a sunburst, with the folder you picked in the centre and each ring one level deeper. If you want SpaceSniffer's boxes, switch to the treemap in Settings: every folder becomes a box inside its parent, with its name and size.

Click a box to zoom in, click the centre or go back to zoom out. The side list shows the biggest items first. Tiny files are grouped so the map doesn't turn into confetti, and you can open the group to see them.

To free space, drag boxes or list rows into the collector. Nothing is deleted yet. Then choose:

• Move to Trash.
• Delete for good.
• Back up to a folder or external drive first, then delete.
• Back up to cloud storage with rclone, then delete.

Like SpaceSniffer, SquirrelDisk keeps the chart up to date when you delete or move files in Finder, Explorer or your file manager. It also:

• shows the real space used on disk;
• counts cloud-only files (iCloud, Dropbox, Google Drive, OneDrive) as zero;
• counts hard links once;
• protects system folders, your home folder and whole drives, and asks for an extra confirmation for app and settings folders.

It's a native Rust app of about 8 MB, with no Electron or web view. It speaks 25 languages and has 7 colour themes.

On Linux

SquirrelDisk ships as an AppImage for x86_64 that runs on X11 and Wayland and updates itself. Make it executable and run it:

chmod +x SquirrelDisk-x86_64.AppImage
./SquirrelDisk-x86_64.AppImage

It reads what your user can read, so folders owned by root may show up smaller than they are. It can also scan a server over SSH without installing anything there. The Linux page covers what usually fills up a Linux disk, from the systemd journal to Docker.

When SpaceSniffer is the better choice

If you're on Windows, SpaceSniffer is a mature, light tool. Pick it when:

• You use filters and tags. SpaceSniffer can filter by name, size or age and lets you tag items with colours. SquirrelDisk has no filters or tags.
• You want a classic treemap with lots of detail. SpaceSniffer shows several levels of nested boxes at once and lets you tune how many.
• You work with NTFS alternate data streams. SpaceSniffer can show them; SquirrelDisk doesn't.

SquirrelDisk makes more sense when you use more than one system, or when you want the backup-then-delete options, or SSH and cloud scanning.

How to get started

1. Go to the download page and get the build for your system: a universal .dmg for Mac, an AppImage or .tar.gz for Linux.
2. Mac: the first time, macOS blocks the app because it isn't signed with an Apple Developer ID. Go to System Settings → Privacy & Security and click Open Anyway.
3. Open Settings and choose the treemap if you want the SpaceSniffer look.
4. Pick a drive or folder, then drag what you don't need into the collector.