TreeSize vs WinDirStat vs Univik: Which to Pick in 2026

TreeSize Professional is the fullest toolkit, with duplicate search, scheduled scans and export to PDF, Excel or HTML. The catch is that those parts are paid and the free build is private use only. WinDirStat is open source, so it is free everywhere, treemap and CSV included, though plainer and slower. Go with TreeSize when you need the extra tools. Go with WinDirStat when the PC is not yours to license. Go with a report-first tool when the job ends in a file you send on.

You need a way to find what is eating a drive, and the two names on the shortlist are TreeSize and WinDirStat. One is a deep commercial toolkit, the other a free open-source classic. The right call comes down to a couple of things you actually need.

Further down you will see where Univik Disk Usage Reporter fits, because the common gap on a work drive is a tidy report you can send without buying a full suite.

📋 On This Page

TreeSize vs WinDirStat: Which Has More Features?
TreeSize Free vs WinDirStat: What Is the Catch?
TreeSize, WinDirStat and Univik Compared
Where TreeSize, WinDirStat and Univik Each Win
Where Univik Disk Usage Reporter Fits In
TreeSize and WinDirStat Questions

TreeSize vs WinDirStat: Which Has More Features?

TreeSize wins on features, clearly. TreeSize Professional from JAM Software adds duplicate search, scheduled scans, deep filters and export to PDF, Excel and HTML on top of the size view. It reads NTFS drives fast and handles network shares. For an admin who lives in storage clean-up, it is a serious toolkit.

WinDirStat keeps things lean. It draws a treemap under a folder tree, marks file types by colour and writes a CSV. Version 2 brought a duplicate finder, which closed one gap, but it is still a focused tool rather than a suite. If you want depth, TreeSize has more. If you want light and quick, WinDirStat is enough.

TreeSize Free vs WinDirStat: What Is the Catch?

Both have a free build, but they are not free in the same way. WinDirStat is open source, so you can run it on any machine at no cost, home or office. TreeSize Free is licensed for private use only. The moment it goes on a work PC you are meant to buy TreeSize Personal or Professional.

There is a feature catch too. TreeSize Free covers the size view, a treemap and a PDF report, which is fine for a home tidy-up. The tools most people upgrade for, such as duplicate search and Excel export, live in the paid editions. So the honest read is that TreeSize Free is a taster and WinDirStat is the whole thing for free.

TreeSize, WinDirStat and Univik Compared

The table below sets the two side by side and adds Univik Disk Usage Reporter as a third column for the report and support angle.

What matters	TreeSize	WinDirStat	Univik Disk Usage Reporter
Scan speed	Fast on NTFS	Slower on big drives	Fast parallel scan
Treemap view	Yes	Yes	Yes, zoomable
Duplicate file search	In paid editions	Yes, in version 2	Planned for Pro
Scheduled scans	In paid editions	No	No
Export formats	PDF, Excel, HTML in Pro	CSV only	HTML and CSV, free
Free edition use	Private use only	Any use, open source	Home and business
Business licence	Needs a paid one	None, open source	None, Pro optional
Vendor support	JAM Software	Community	Email and live chat
Learning curve	Deep, many options	Plain and simple	Simple, report-first
Best fit	A full toolkit for a fee	A free tool for any PC	A quick report with help

The shape of it: TreeSize gives the most for a fee. WinDirStat gives a solid tool for nothing. Univik sits in the middle with a free report and a team to ask.

Where TreeSize, WinDirStat and Univik Each Win

TreeSize is the choice for a power user who wants everything in one window. The Professional edition finds duplicates, runs on a schedule, filters hard and exports to Excel, PDF or HTML. The price of that depth is the licence cost and a free build limited to private use.

WinDirStat is the pick when budget is zero and the PC is not yours to license. It costs nothing and the source is open. Version 2 even added a duplicate finder. It looks dated beside TreeSize and slows on a huge drive, yet the price and freedom keep it in use.

Univik Disk Usage Reporter is the one for people who mostly need a clear report at the end. It scans a drive for folder sizes, shows a treemap and pulls up the largest files. Even the free edition can write out an HTML or CSV summary. It is lighter than TreeSize Pro and comes with support.

Where Univik Disk Usage Reporter Fits In

TreeSize can do almost anything, but you pay for the suite and the free build will not follow you to the office. WinDirStat is free but stops at a CSV. On a work or client drive the thing you usually need is a report you can hand over, without a full toolkit and without a private-use limit. That is the spot Univik Disk Usage Reporter aims at.

Point it at a drive and it scans in parallel, then shows the outcome in a single view. You get a ranked folder list, a treemap to drill into, the heaviest files with their paths and a per-extension tally. One click in Export saves all of that as an HTML page you can print or a CSV for a spreadsheet. Nothing leaves your computer. With email and live-chat support behind it, the free download is an easy first step.

TreeSize is a fine suite if you will use every feature. Most people we talk to only need a clear report and a person to ask. We built for that, not for a feature count.

Nick Rogers, Founder, Univik

A disk space report without the price tag

Univik Disk Usage Reporter turns a drive into a ranked folder view, a treemap and a heaviest-files list, then saves the lot as an HTML or CSV report. Free to begin, no sign-up.

⬇️ Download Free Visit the product page →

Runs offline on Windows 7 to 11 · no account needed

The short version

TreeSize Professional has the most features, including duplicate search and export to Excel and PDF.
TreeSize Free is limited to private use, so a work PC needs a paid licence.
WinDirStat is free everywhere because it is open source, with a treemap and CSV export.
WinDirStat is slower and plainer, but it costs nothing anywhere.
Univik Disk Usage Reporter gives an HTML report and support in a free edition with no private-use limit.

Try Univik Disk Usage Reporter free

TreeSize and WinDirStat Questions

Is TreeSize better than WinDirStat?

TreeSize Professional has more features, such as duplicate search, scheduled scans and export to Excel or PDF. WinDirStat is simpler and open source, which keeps it free everywhere. TreeSize is the deeper toolkit for a price. WinDirStat is the free workhorse. Your pick turns on how much you need beyond a plain scan.

Is TreeSize Free enough, or do I need the paid version?

TreeSize Free shows folder sizes and a treemap and can save a PDF report, which covers a quick home clean-up. The catches are that TreeSize Free is licensed for private use only and the stronger tools such as duplicate search and Excel export sit behind the paid Personal or Professional editions.

Can I use TreeSize and WinDirStat for free at work?

Only one of them. WinDirStat is open source, so it runs free on a work PC. TreeSize Free is for private use only, which means a company machine needs a paid TreeSize Personal or Professional licence from JAM Software. That licensing line is the first thing to check before you install either at the office.

Which is faster, TreeSize or WinDirStat?

TreeSize is faster on NTFS drives because it can read the file table for a quick scan, much like a modern analyzer does. WinDirStat walks every folder in turn, which is thorough but takes longer once a drive holds millions of files. For a fast scan on a large disk, TreeSize has the edge.

Which disk tool gives a report I can hand over?

TreeSize Professional exports to PDF, Excel and HTML, though that sits in the paid edition. WinDirStat only writes a CSV. Univik Disk Usage Reporter, in its free edition, writes an HTML file any browser can open plus a CSV, so a clean result goes to IT without a paid upgrade.

What is a good TreeSize or WinDirStat alternative?

If TreeSize feels heavy or its private-use limit blocks you, and WinDirStat feels too bare, Univik Disk Usage Reporter sits in between. It scans quickly and puts folder sizes beside a treemap and the largest files. The result saves as an HTML page or a CSV file. It is free to start with real support behind it.

About This Guide

This TreeSize and WinDirStat comparison was researched by the Univik team and edited by Leena Taylor Paul. Univik has made Windows disk and file utilities since 2013. Feature, price and licence details were confirmed on each product's own site during September 2026. Reviewed 22 September 2026. Not sure which one fits? The support team can help from the link above.

Sources checked: TreeSize by JAM Software · WinDirStat project · Univik Disk Usage Reporter