Diskflag / Guides / WizTree vs WinDirStat

WizTree vs WinDirStat

By Scott Foster, founder of DiskflagUpdated October 24, 2026

WizTree is best for raw speed and is free for personal use. WinDirStat is best if you want free and open source, including at work, and it now also reads the MFT when run elevated (since 2.5.0). Neither tells you which folders are safe to delete.

Both tools map a Windows drive by size so you can see what is filling it. They differ on licence, features and how they scan. Facts below are from the vendors' own pages as of October 24, 2026, and I link each source.

How do WizTree and WinDirStat compare side by side?

Sources: diskanalyzer.com, WizTree download page, WizTree guide, WizTree licensing, WinDirStat on GitHub, WinDirStat releases and WinDirStat changelog. "Not documented" means I did not find it on those pages.

Which is faster, WizTree or WinDirStat?

WizTree is built around speed. It reads the NTFS Master File Table directly when you run it as administrator, which is why it finishes scans so quickly.

WinDirStat used to walk the folder tree instead. Since version 2.5.0 it also scans the MFT directly when run elevated, so the gap should be smaller when both run as administrator.

I have no head-to-head timings for these two, so I won't quote any. If speed matters, run both as administrator on your own drive and compare.

How do the features differ?

WinDirStat shows more views: treemap, sunburst and flame graph, plus file-type statistics and largest-file lists. It also has duplicate detection, cleanup tools and custom cleanup commands. You run those yourself. Nothing is flagged for you.

WizTree gives you a tree view beside a treemap, a largest-files list, a duplicate finder and CSV export. The duplicate finder matches by name, size and date, not by content, so treat its matches as candidates.

Dark mode is documented for WinDirStat (since 2.5.0). I found no documentation for it in WizTree.

What do they cost, and can I use WizTree at work for free?

WinDirStat is free and open source under GPL v3+. That covers home and work.

WizTree is free for personal use. Commercial use needs a Supporter Code (source):

• Individual: $25
• Micro (up to 5 staff): $100
• Small (20): $200
• Medium (50): $350
• Large (100): $500

So no, you can't use the free version of WizTree at work. A free tool at work is a reason to pick WinDirStat.

Is WizTree safe?

WizTree is proprietary software published at diskanalyzer.com. Download it only from that site, not from mirrors or search ads.

It reads file metadata, and it asks for administrator rights so it can read the NTFS MFT. Only grant that to a copy you got from the official site.

Is WinDirStat safe?

WinDirStat is open source (GPL v3+). Its code and releases are public on GitHub. Download it only from there.

Open source means anyone can read the code. Its cleanup tools act on files when you tell them to, so check each path before you run one.

What are the pros and cons of each?

WizTree

WinDirStat

Which should you pick?

• Pick WizTree if you want the fastest scan and use it only for personal use.
• Pick WinDirStat if you want free and open source, or need a free tool at work.
• Either one works for a quick look at where the space went.

Looking at more options? See the best disk space analyzers for Windows and WinDirStat alternatives.

What if you want to know what is safe to delete?

Neither tool answers that. They show sizes. You still have to know whether a 112 GB file is a Docker disk you can prune or something Windows needs.

Diskflag is a disk space analyzer for Windows 10 and 11 that flags what is safe to clear. It maps the drive as a treemap and marks items safe to clear, worth reviewing or managed by Windows. It only moves things to the Recycle Bin, after you confirm.

It has trade-offs. It is slower than WizTree because it uses standard Windows file APIs, not the MFT. On my 1 TB C: drive with 4.9 million files, a first scan took about 3.5 minutes. It costs $8 once, where WinDirStat and personal-use WizTree are free. It runs on Windows only. It is not code-signed yet, so Windows SmartScreen shows a notice the first time you run it.

Once you know what is safe, free up space on your C drive step by step, or read what is safe to delete on Windows.

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