One script that answers "where did my 250 GB go?". It scans a directory recursively, prints the largest subdirectories to the console and writes an interactive HTML treemap: rectangle area equals disk usage, click to drill down.
Works on Windows 11, Linux and macOS with CPython >= 3.7.
- One file, one dependency – dirtree.py plus plotly
- Interactive – click a rectangle to zoom in, click the header bar to go back up
- Console summary – top-N largest directories, no browser needed
- Loop-safe – symlinks are skipped, Windows junctions are caught by a device/inode guard, so C:\ cannot walk in circles
- du-like accounting – hardlinked files counted once (where the OS reports link counts), -x stays on one filesystem / drive
- Robust – permission-denied and unreadable entries are counted and skipped, never fatal
python3 -m venv .venv
source .venv/bin/activate # Windows: .venv\Scripts\activate
pip install -r requirements.txtpython dirtree.py . # current directory
python dirtree.py C:\ # whole drive (Windows)
python dirtree.py / -x # root filesystem (Linux/macOS)
python dirtree.py C:\ --min-mb 500 # hide clutter below 500 MB
python dirtree.py /var --no-browser # just write the HTMLExample output:
Scanning: /home/user/projects
This may take a little while on large drives...
Total: 42.0 MB
Directories scanned: 5
Largest directories:
----------------------------------------------------------------------
30.0 MB big
12.0 MB nested/deep
12.0 MB nested
4.0 KB small
Interactive map written to:
/home/user/projects/dirtree.html
| Option | Default | Meaning |
|---|---|---|
| path | . | directory to scan |
| --min-mb | 10 | hide directories below this size in the treemap |
| -x, --one-filesystem | off | do not cross mount points / drive boundaries (like du -x) |
| --top | 25 | how many directories to list on the console |
| --output | dirtree.html | HTML output file |
| --no-browser | off | do not open the result in a browser |
- Linux/macOS – scanning / without -x descends into every mounted filesystem (NAS shares, external disks, Docker volumes, /proc, /sys), which makes the total confusing. Use -x for a du -x-style view.
- Windows – st_ino/st_nlink are not filled in by scandir, so hardlinks (rare on Windows) may be counted per link. Paths longer than 260 characters are skipped and reported in the "inaccessible entries" count unless long path support is enabled in the OS.
- Sizes are apparent file sizes (st_size), not allocated blocks, so sparse files and compressed filesystems can differ from what the OS reports.
GPLv3 (c) 2026 mail@marcelpetrick.it
Contributions welcome!