TreeSize Free
Active · Website · Store listing
Freeware disk-space manager from JAM Software (Trier, Germany): scans local drives and MTP/WebDAV-connected mobile devices, sizes folders down to file level, draws the classic TreeSize treemap, integrates into Windows Explorer, and exports PDF reports - the no-cost entry of the TreeSize family, sharing the paid editions' code base. The 1996 original that spawned JAM Software itself.
- Platforms
- Interface
- Tech stack
- Closed source Win32
- Features
- Dev-junk cleaning
- Not a focus
- Development
- Company team · original author still leadsjam-softwareJAM Software GmbH, Trier, Germany - founded by Joachim Marder, who still leads it; ~30 employees.
- License
- ProprietaryFreeware for private, non-commercial use
- Price
- FreeFree for private/non-commercial use; paid Personal/Professional editions sold separately
- Launched
- first_release_at
- First release
- Domain registered
- (jam-software.com)
- Last seen alive
Checks
Mechanical checks derived from the fields above. Each row is one fact; "not yet checked" means exactly that, not a failure. There is no composite score; read them together.
| Track record | about 30 years |
|---|---|
| Source published | No |
| Release signing | Signed |
| Security contact | None found |
| Reproducible builds | Not yet checked |
| Telemetry | Unknown |
| Runs elevated | Only when needed |
| Auto-update channel | Unknown |
| Recent activity | Last seen 2 days ago |
- JAM installers are Authenticode-signed; MS Store listing is the vendor's own (publisher 'JAM Software')
- Admin elevation is offered for scanning protected directories
- Built-in update check plus a Store channel; update-package signing not verified
- No dedicated security contact found; support via JAM's help center
Relations
- same author TreeSize (Personal / Professional)
The paid siblings on the same code base: add deduplication search, file operations, scheduled scans, and server/cloud targets.
- same author SpaceObServer
JAM's enterprise storage-monitoring server ($600/instance/year) - what TreeSize grows into for datacenters.
- same author UltraSearch
JAM's other freeware - instant file search via the NTFS MFT.
Research notes
- The 1996 original: written in a Trier student flat by 24-year-old CS student Joachim Marder as a GUI version of the Unix 'du' for Windows 95 - 'Es fehlte ein Programm, um komfortabel die Belegung der Festplatte analysieren zu können' (Volksfreund profile). Freeware from day one.
- Download traffic on the university-hosted page grew so heavy the computer center complained, forcing a dedicated domain in 1997 - the event that turned a student project into JAM Software (registered Jan 1, 1998).
- Free tier is a deliberate, defended commitment rather than a trial: 'We will definitely continue to pursue TreeSize Free as a project. I think it's important to offer a free version in addition to the commercial one.' - founder Joachim Marder in the 25-year retrospective.
- Licensed for private/non-commercial use only; MTP/WebDAV mobile-device scanning since v3.4; current freeware line is v4.8.x (Mar 2026).
Sources
| URL | Role | Status | Checked | Archive |
|---|---|---|---|---|
| www.jam-software.com/treesize_free | homepage | 200 | ||
| apps.microsoft.com/detail/xp9m26rsclnt88 | store_listing | 403 | ||
| www.jam-software.com/treesize/treesize-turns-25.shtml | other | 200 |
Established alternatives
Related tools
Wrong, stale, or missing something? Flag this listing: corrections reach the site operator, not TreeSize Free's developer. Last reviewed .