WinDirStat (Windows Directory Statistics) is a free, open-source disk usage analyzer and cleanup assistant for Microsoft Windows. It scans drives or folders, shows which files and folders occupy the space, and offers tools to export and clean up what it finds.
Choosing what to scan
A scan can cover all local drives at once, selected drives, or one or more folders and UNC paths entered together. Targets can include network shares and phones or other MTP devices. With administrator rights on a local NTFS drive, WinDirStat reads the Master File Table directly instead of walking each folder. This makes the scan much faster. You can pause a running scan and refresh one subtree after files change.
Scan filters include or exclude folder paths and file name patterns, and can skip files above or below a size or age. By default, WinDirStat leaves out junctions, symbolic links and mount points so it does not count anything twice.
Treemaps and other views of one scan
WinDirStat presents a scan in linked views. The file tree lists each folder with a size bar, percentage, item counts and last change date. A file type list groups everything by extension with total bytes and a color for each type.
The treemap draws every file as a rectangle whose area matches its size, using the same type colors. A large block of one color therefore points to a group of large files of one kind. A sunburst shows folder depth as rings, and a flame graph shows it as stacked bars. Clicking a shape selects the matching item in the tree. A separate tab lists the largest individual files.
WinDirStat can measure sizes as logical length or as physical space allocated on disk. The two differ for compressed, sparse and hardlinked files. Optional entries show free space and an “unknown” amount that Windows reports as used but the scan could not account for.
Search and duplicate files
After a scan, WinDirStat can search file and folder names with wildcards or regular expressions, limited by size range or owner. Duplicate detection first groups files by size and then hashes those with matching sizes with a selectable algorithm. Optional sparse hashing compares four samples from files over 64 MiB and labels the results as probable duplicates. WinDirStat skips cloud placeholders by default.
Cleanup actions
You can move selected items, send them to the Recycle Bin or delete them permanently. Other actions apply NTFS compression, convert zero-filled ranges into sparse regions, remove empty folders, or replace confirmed duplicates on the same volume with hardlinks to a single copy. A Windows tools menu empties Recycle Bins, disables the hibernation file, starts Disk Cleanup and removes shadow copies. User-defined cleanups run custom commands with placeholders for the selected path or name.
Permissions, storage costs and reports
A permissions scan lists allow and deny entries for the scanned items. It shows inherited entries at the root and explicit entries below it, and can highlight chosen accounts. Storage Analytics sorts files into hot, cool, cold and archive tiers by days since last change. It uses prices entered by the user to compare the cost of keeping everything in the hot tier with a tiered layout. WinDirStat can also watch the file system for changes.
You can save scans as CSV or JSON snapshots and reopen them later without rescanning. Command-line options run a scan and write scan, duplicate or permission reports without opening the main window.
Recovering deleted files
On local NTFS, exFAT and FAT drives, WinDirStat can try to recover deleted files when run as administrator. Success depends on whether the file’s metadata and data still remain on the drive.
