When a Windows workstation starts running low on disk space, the first question is always the same: where did all the storage go? Built-in Windows tools like Settings → Storage can give you a high-level breakdown, but for serious investigation you need a dedicated disk space analyzer — a tool that scans every file and folder, then visualizes the results so you can spot the culprits in seconds instead of hours.
In this article we benchmark three of the most popular analyzers available for Windows in 2024: WizTree, TreeSize, and WinDirStat. All three were tested on the same machine under identical conditions. Our goal is not to declare a single "winner" — the right choice depends on your specific needs — but to give you hard numbers and honest impressions so you can make an informed decision.
Test Environment
All benchmarks were performed on the following hardware:
- Machine: Dell OptiPlex 7090 Micro
- CPU: Intel Core i7-11700 (8 cores, 16 threads)
- RAM: 32 GB DDR4-3200
- Storage: Samsung 970 EVO Plus 1 TB NVMe SSD (formatted NTFS, 847 GB used)
- OS: Windows 11 Pro 23H2 (build 22631.3880)
Each tool was tested three times. We cleared the Windows file-system cache between runs using purgestandby from Sysinternals RAMMap to ensure consistent cold-start measurements.
WizTree 4.19
WizTree takes a fundamentally different approach from most disk analyzers. On NTFS volumes it reads the Master File Table (MFT) directly rather than walking the file system tree. The MFT is a compact index that NTFS maintains for every file and folder on the volume, and reading it sequentially is vastly faster than issuing millions of individual FindFirstFile / FindNextFile API calls.
Scan speed
On our 847 GB test volume (approximately 1.2 million files in 98,000 folders), WizTree completed a full scan in 3.8 seconds on average. That is not a typo — under four seconds for nearly a terabyte of data. For non-NTFS volumes (FAT32, exFAT, or network drives), WizTree falls back to a standard file-system walk, which is slower but still competitive.
Visualization
WizTree offers two primary views: a sortable file list (filterable by name, extension, size, and date) and a treemap that represents every file as a colored rectangle proportional to its size. The treemap is responsive and updates in real time as you navigate folders. You can click any rectangle to jump to that file's location.
Memory usage
Peak RAM consumption during scan was 210 MB. After the scan completed and the UI settled, working set dropped to around 165 MB. This is quite reasonable for the amount of data indexed.
Licensing
WizTree is available under a personal-use license at no charge. Commercial use requires a paid license. The developer, Antibody Software, offers volume licensing for organizations.
TreeSize (JAM Software)
TreeSize has been a staple in the Windows IT toolkit for over two decades. The Professional edition is a commercial product aimed at system administrators; a simpler edition is also available.
Scan speed
TreeSize Professional uses multi-threaded file-system enumeration. On our test volume it completed a full scan in 27.4 seconds on average — roughly seven times slower than WizTree's MFT approach, but still fast enough for most production workflows.
Visualization
TreeSize offers the widest variety of views: treemap, sunburst chart, pie chart, bar chart, and the classic hierarchical folder tree with size bars. It also includes a built-in file search, duplicate finder, and export to Excel/PDF. For reporting-heavy environments, TreeSize is hard to beat.
Memory usage
Peak RAM during scan was 380 MB, settling to about 290 MB after completion. The richer feature set and larger UI framework contribute to higher memory consumption compared to WizTree.
Licensing
TreeSize Professional is a commercial product with per-seat or per-server licensing. JAM Software offers a 30-day evaluation period. A simpler version of the product is available at no cost for basic scanning needs.
WinDirStat 1.1.2
WinDirStat (Windows Directory Statistics) is an open-source project that has been around since 2003. Despite its age, it remains popular thanks to its zero-cost license, straightforward interface, and the distinctive "cushion treemap" visualization it popularized.
Scan speed
WinDirStat is single-threaded, which means it cannot take advantage of modern multi-core CPUs during scanning. On our test volume it took 44.6 seconds on average — more than ten times slower than WizTree and nearly twice as slow as TreeSize. On spinning hard drives or larger volumes, the difference becomes even more pronounced.
Visualization
WinDirStat's signature feature is the cushion treemap at the bottom of the window, where each file type is assigned a distinct color. This makes it easy to spot, for example, that video files (green) dominate a particular folder. The top half of the window shows a traditional folder tree with percentage bars.
Memory usage
Despite the smaller feature set, WinDirStat consumed 420 MB of RAM at peak — the highest of the three tools. The single-threaded architecture and older memory management appear to be factors. Working set after scan completion was around 350 MB.
Licensing
WinDirStat is released under the GNU General Public License (GPL). It is open-source and available at no cost for any purpose, including commercial use.
Head-to-Head Summary
| Metric | WizTree 4.19 | TreeSize Pro | WinDirStat 1.1.2 |
|---|---|---|---|
| Scan time (847 GB NTFS) | 3.8 s | 27.4 s | 44.6 s |
| Peak RAM | 210 MB | 380 MB | 420 MB |
| Threading | MFT + multi-thread | Multi-thread | Single-thread |
| Treemap | Yes | Yes + sunburst | Yes (cushion) |
| Export/report | CSV | Excel, PDF, CSV | None |
| Duplicate finder | No | Yes | No |
| Network drives | Yes (slower) | Yes | Yes |
| License | Personal / Commercial | Commercial (trial) | GPL (open-source) |
Which Tool Should You Choose?
Choose WizTree if…
- Speed is your top priority and most of your volumes are NTFS
- You need a lightweight tool that runs quickly even on older hardware
- You primarily work on individual Windows workstations
- You value a clean, straightforward interface without excess features
Choose TreeSize Professional if…
- You need enterprise-grade reporting (Excel, PDF, scheduled scans)
- Built-in duplicate detection is important to your workflow
- You manage diverse environments including network shares and servers
- Budget permits a commercial license and you want vendor support
Choose WinDirStat if…
- You need a tool with no licensing restrictions whatsoever
- The cushion treemap with color-coded file types matches your visual preference
- Scan speed is secondary to having an open-source, auditable codebase
Our Recommendation
For most IT professionals managing Windows workstations, WizTree offers the strongest combination of speed, usability, and low resource consumption. Its MFT-based scanning is a genuine technological advantage that no other tool in this comparison can match. When we conduct disk space audits for clients, WizTree is often our first-pass tool because it delivers a complete picture in seconds rather than minutes.
That said, TreeSize Professional earns its place in environments where reporting, scheduling, and duplicate detection justify the license cost. And WinDirStat remains a solid choice for teams that prioritize open-source licensing above all else.
The good news is that all three tools can coexist on the same machine. Many of our clients use WizTree for day-to-day quick scans and TreeSize for monthly compliance reports. There is no need to commit to just one.
Need help deciding which tool fits your organization? Our Tool Evaluation service benchmarks disk analyzers against your actual workload and delivers a customized recommendation. Get in touch to learn more.