Your C: drive is full, but Windows won't tell you why. DiskLens scans your drive, calculates real folder sizes including everything nested inside, and shows the biggest space hogs at the top so you can drill straight to the problem.
Built-in Windows storage tools show you top-level categories or a flat file list. They never answer the real question: which folder is actually holding 80 GB? DiskLens walks your entire folder tree, calculates true recursive totals for each directory, and sorts biggest-first. Within seconds you're looking at the exact folder responsible for the bulk of your disk use.
The tool stays completely read-only. It inspects file sizes and reports them back to you—it never modifies, moves, or deletes anything on its own. After you've identified the culprit, you open its location in File Explorer and decide what to archive, move, or remove yourself.
**Your Documents folder ballooned.** Point DiskLens at C:\Users\YourName and scan. You'll instantly see whether Downloads, Desktop, or AppData is the culprit, then drill into that folder to find the specific subdirectory.
**Program Files is mysteriously huge.** Scan the Program Files folder and rank everything by size. Games and development tools often hide gigabytes of cached data in their installation directories.
**You need space but don't know what to delete.** Run DiskLens on your entire drive, look at the top results, and examine each one. Once you've identified candidates—old backups, duplicate photos, abandoned projects—you handle cleanup yourself in File Explorer, so you're in full control.
**You want to move files before removing them.** DiskLens shows you the size accurately, so you know exactly how much space you're freeing up. The tool is read-only, so you manage the actual move or delete operation yourself.
No account, no sign-up. The scan happens entirely on your PC.
Runs on your Windows PC. Keep the installer handy, or uninstall it through Windows settings whenever you're done.
Light on resources. Runs on budget mini PCs and aging laptops without complaint. You don't need a powerful machine to find out what's eating your storage.
Source code is open under MIT. Free to download, free to use, free to share.
Not for ordinary user folders and drives. Some protected system paths require elevation to read, but for a normal 'where did my space go' scan you can run DiskLens as a standard user.
No. Everything runs locally on your machine. You can unplug the ethernet cable and it works exactly the same.
Yes. It's read-only—it inspects file sizes and never modifies, moves, or deletes anything. You decide what to clean up afterwards in File Explorer.
Yes. Both Windows 10 and Windows 11, 64-bit, are supported with the same build.