Disk Usage Analyzer for Windows – Find Large Folders Fast

Your C: drive is full and you have no idea why. DiskLens scans any Windows drive or folder, calculates true folder sizes including everything nested inside, and ranks them biggest-first so you can see exactly which directory is holding 80 GB.

Why the Built-In Windows Storage View Isn't Enough

Windows Settings → Storage shows you categories like Documents, Pictures, and Other — but not which single folder is actually the culprit. DiskLens walks the entire folder tree on your drive, sums up every file and subfolder under each entry, and sorts by size. Within seconds you're looking at the exact directory responsible for the bulk.

The tool never modifies anything. It only reads file sizes and reports back. You open File Explorer afterwards and decide what to archive, move, or delete yourself.

What Makes DiskLens Different

Most disk analyzers show you either categories or a flat file list. DiskLens shows you recursive folder totals — a 50 GB folder really is 50 GB, including all hidden files and nested subfolders deep inside it. Results are always sorted by actual disk use, so you never waste time on small folders.

Download the zip and run the standard Windows installer. Windows may ask for permission once.

It works offline. Scans happen entirely on your machine. Your data never leaves your PC.

How to Use DiskLens

Download the zip and run the installer Download the zip and run the standard Windows installer. Windows may ask for permission once.
Click Browse and pick a target Point it at your C: drive, a user profile like C:/Users/YourName, or a specific folder like Downloads or Program Files. Folder suspected of being large? Scan that too.
Click Scan and wait Large drives take a few seconds longer on the first run. Small folders scan almost instantly. Watch the progress and let it finish.
Look at the top result The biggest folder appears at the top of the list. That's your space hog. Select it and run Scan again to drill down into what's inside.
Repeat until you find the culprit Keep drilling into subfolders until you identify the specific files or directories worth cleaning up. Then manage them in File Explorer yourself.

Frequently Asked Questions

Is DiskLens really free?

Yes. Free to download, free to use, open source under MIT. No trial window, no paid tier, no watermarks.

Does it work on Windows 11?

Yes. Both Windows 10 and Windows 11, 64-bit, are supported with the same build.

How do I install it?

Not for everyday scans of user folders and drives. Some protected system paths require elevation, but a normal 'where did my space go' sweep works fine as a standard user.

Does it need an internet connection?

No. Everything runs locally on your PC. You can unplug ethernet and it works exactly the same.

Is it safe?

It's read-only by design. It inspects file sizes and never deletes, moves, or edits anything on its own. You decide what to clean up afterwards.

Can I run it from a USB stick?