SpaceSniffer for Linux: the closest alternatives

• What made SpaceSniffer good
• Storage Sifter
• baobab
• Filelight
• ncdu
• Quick comparison
• One thing to know before you start deleting

SpaceSniffer is one of those small Windows tools people genuinely miss. It scans fast, it draws a treemap you can read at a glance, and you can dig into a folder by clicking it. There is no Linux build and there never has been.

Here is what to use instead, and where each one differs from what you are used to.

What made SpaceSniffer good#

Worth naming, because it is the checklist for a replacement:

1. Immediate visual answer. A treemap where big things look big.
2. Zoom into any folder and the view re-tiles around it.
3. Fast scanning, with results appearing while it works.
4. Portable, no installation.

All four are available on Linux. The last one maps to an AppImage.

Storage Sifter#

Storage Sifter is ours, and it is the closest match to the SpaceSniffer feel: a squarified treemap, GPU-rendered so it stays smooth on large filesystems, click any rectangle to drill in with a breadcrumb tracking where you are, and live progress while it scans (items found, size, elapsed time, scan rate, and an estimate for a whole-disk pass).

Two things SpaceSniffer does not do:

• Colour by what a file is, rather than by extension. Caches and build artifacts, media, applications and libraries, and source code each get their own colour, so you can read the shape of a drive before you click anything.
• A "safe to delete?" verdict. Right-click any item and it tells you what the path actually is and whether it is reclaimable, with the correct cleanup command for your package manager where one exists. That is the step every other tool leaves entirely to you, and it is where people make expensive mistakes.

It moves to trash by default, tiers the confirmation for permanent deletes, and refuses protected system roots. Free, open source (MIT), no telemetry, nothing leaves your machine.

Available as an AppImage (the portable option), from the AUR on Arch, or via Cargo.

baobab#

GNOME's Disk Usage Analyzer, and probably already installed. Rings instead of a treemap. If you want an answer immediately and do not want to install anything, start here. It is solid and it does exactly one thing.

Filelight#

The KDE version, same ring layout, quick, and well integrated with Dolphin. If you are in Plasma it is the equivalent starting point.

ncdu#

Terminal, not visual. Different tool for a different situation: a server you are SSH'd into, where nothing graphical is an option. Fast and genuinely pleasant to use with the keyboard. Install it on your servers now rather than when you need it.

Quick comparison#

There is a longer, more honest version of this table, including the cases where ours is the wrong pick, in Linux disk usage tools compared.

One thing to know before you start deleting#

On Linux the space is often not where a Windows habit expects. Before hunting through personal files, check the caches: journalctl --disk-usage for systemd logs, docker system df if you use Docker at all, ~/.cache for browser and build leftovers, and your package manager's cache directory. Those four are frequently most of the problem, and clearing them is close to risk-free.

The full walkthrough, including what to do when the disk reports full but nothing adds up, is in how to find what is using disk space on Linux.

Storage Sifter is built by Fopull LLC, a software studio in Knoxville, TN. Source on GitHub.