WinDirStat
FreeOne picture showing exactly what filled your drive
A disk space visualizer. After scanning, it renders every file as a rectangle in a treemap where area equals size and color indicates type — whatever is consuming your drive is immediately visible, and one click locates its exact path. The installer is about 3 MB.
Why we picked it
"The C drive is full" is the classic Windows problem, and the built-in storage settings only tell you "Apps 40 GB, Documents 15 GB, Other 80 GB" — without ever explaining what "Other" is. Clicking through folder properties one level at a time takes all evening.
WinDirStat's approach is to draw the entire disk as a picture. After scanning, every file becomes a rectangle whose area is proportional to its size, colored by type. The result: the 30 GB hibernation file, the forgotten virtual machine image, three years of accumulated installers all appear as enormous blocks you cannot miss. Click one and the directory tree above expands straight to it.
A treemap communicates this better than any list could — you do not need to know what you are looking for, because the anomaly announces itself.
Practical details:
- Three-pane layout: directory tree sorted by size at top, file type statistics on the right, treemap below, all linked so clicking anywhere synchronizes the others.
- Act directly: right-click to delete, open the containing folder or copy the path.
- Scan multiple drives at once, or restrict to a single directory.
- v2 is a rewrite. The current v2.8.0 (August 2026) is far faster than the long-dormant 1.1.2, supports long paths, has a dark theme, and correctly handles modern Windows constructs like deduplicated, sparse and cloud placeholder files. If your memory of WinDirStat is the slow old version, it is worth another look.
To be clear about:
- Windows only. macOS has GrandPerspective and the paid DaisyDisk; Linux has Baobab (usually preinstalled) and ncdu on the command line.
- Run as administrator when scanning a system drive, or some system directories are unreadable and the totals will be wrong.
- Do not delete large files reflexively.
hiberfil.sys(hibernation),pagefile.sys(virtual memory) and the WinSxS directory are all in active use by Windows, and deleting them directly causes problems — they must be disabled or cleaned through the system's own mechanisms. Look up what a file does before removing it.
It is a tool you never think about until the drive turns red, and at 3 MB it costs nothing to keep around.