Weasis is a free, open-source DICOM viewer for Windows, macOS and Linux, used by hospitals, universities, dental clinics and imaging researchers. For dental teams it is a vendor-neutral way to open CBCT, panoramic and intraoral DICOM files from any manufacturer, without the software that came with the X-ray unit.
A Weasis download gives you a full desktop viewer: multiplanar and curved reconstructions, 3D volume rendering, measurements, PACS and DICOMweb connectivity, and export to CD/DVD with the viewer embedded. It is dual-licensed under the Eclipse Public License 2.0 and Apache 2.0, and development is active, with several releases a year.
Weasis at a glance
| Item | Details |
|---|---|
| Latest version | 4.7.3 (25 August 2026) |
| Licence | Free and open source, EPL 2.0 or Apache 2.0 |
| Platforms | Windows 10 or later (x86-64); macOS 11+ on Intel, macOS 12+ on Apple Silicon; Linux (DEB, RPM, Flatpak, Snap) |
| Developer | Weasis team, led by Nicolas Roduit |
| Official website | weasis.org |
| Best for | Opening CBCT and X-ray DICOM from any vendor; building panoramic and cross-sectional views from CBCT |
What it does
- Opens standard DICOM files, DICOMDIR discs and DICOM ZIP archives, including JPEG, JPEG-LS, JPEG 2000 and JPEG-XL compressed images.
- Oblique multiplanar reconstruction (MPR) with MIP, MinIP and mean projections.
- Curved MPR: trace a curve on an axial slice, typically along the dental arch of a CBCT, to build a panoramic view and cross-sectional slices.
- 3D volume rendering with presets and adjustable lookup tables.
- Measurements: length, area, angle, perpendicular and parallel lines, free-shape regions, pixel statistics and histograms.
- PACS query/retrieve (C-FIND, C-GET, C-MOVE), sending to PACS, and DICOMweb (QIDO-RS, WADO-RS, STOW-RS).
- Export to DICOMDIR, ZIP, an ISO image with Weasis embedded, or JPEG, PNG and TIFF images.
- Dicomizer: converts photos, videos, PDFs and STL meshes into DICOM so they can be stored with the patient’s imaging.
How dental teams use it
Opening a CBCT disc from another clinic
- Copy the disc contents to a local folder.
- In Weasis, import the folder (or the DICOMDIR file) and open the CBCT series.
- Scroll the axial slices, then open the MPR view to see coronal and sagittal planes side by side.
Building a panoramic view and cross-sections
- Open the CBCT volume and start the curved MPR tool.
- On an axial slice at root level, click points along the centre of the arch.
- Weasis builds a panoramic-style reformation and cross-sections perpendicular to the curve.
- Measure bone height and width on the cross-sections with the length tool.
Sending a scan to a referring dentist
- Select the study and choose DICOM export.
- Export as an ISO image with Weasis embedded (for a disc) or as a ZIP archive.
- The recipient can then open the study without installing vendor software.
Keeping photos and scans with the imaging record
Use the Dicomizer to turn intraoral photos, PDF reports or STL scans into DICOM objects linked to the patient, then send them to the clinic PACS.
Install and first run
- Windows: run the MSI installer (Windows 10 or later). IT staff can deploy it with
winget install WeasisTeam.Weasisorchoco install weasis. It is also listed in the Microsoft Store. - macOS: use the PKG that matches your Mac (Apple Silicon or Intel), or
brew install --cask weasis. - Linux: DEB and RPM packages, or
flatpak install flathub io.github.nroduit.Weasis, orsudo snap install weasis. The Flatpak and Snap sandboxes can restrict access to removable media such as discs. - No Java setup needed: current builds bundle everything they need.
- 3D gotcha: volume rendering needs working GPU drivers. If 3D views stay blank, update the graphics driver.
Limitations
- The open-source distribution is not a certified medical device (CE or FDA). The developers state that any primary diagnostic use requires you to comply with the rules in your jurisdiction.
- No implant planning, implant libraries or surgical guide design.
- It displays DICOM segmentations but is not a segmentation tool. Use 3D Slicer or ITK-SNAP to segment teeth or jaws.
- No STL export of 3D models; STL files can only be imported and wrapped as DICOM.
- Desktop only: no Android or iOS app.
Weasis vs alternatives
| Tool | Licence | Platforms | Key difference |
|---|---|---|---|
| Weasis | Free, open source | Windows, macOS, Linux | Curved MPR for CBCT, strong PACS and DICOMweb support |
| RadiAnt DICOM Viewer | Shareware (conditionally free) | Windows | Very fast, STL export, no curved MPR |
| Horos | Free, open source | macOS only | Curved MPR and STL export on the Mac |
| 3D Slicer | Free, open source | Windows, macOS, Linux | Segmentation and 3D modelling rather than day-to-day viewing |
FAQ
Is Weasis free?
Yes. Weasis is free and open source, dual-licensed under EPL 2.0 and Apache 2.0.
Is Weasis safe?
The installers are code-signed, the source code is public, and every build is scanned by SonarCloud. Download it from the official site or a trusted package manager.
Is there Weasis for Mac?
Yes. There are separate macOS packages for Apple Silicon (macOS 12 or later) and Intel Macs (macOS 11 or later).
Is Weasis available for Android or iPhone?
No. Weasis is a desktop viewer for Windows, macOS and Linux.
Does Weasis run on Windows 7?
The current Windows installer requires Windows 10 or later.
How do I measure in Weasis?
Pick the measurement tool from the toolbar (length, angle, area and others) and click on the image. Distances are calibrated from the pixel spacing in the DICOM file when it is present.
Weasis vs RadiAnt: which is better?
Weasis is free, cross-platform and has curved MPR for CBCT. RadiAnt is Windows-only shareware built for speed, and it can export STL models.
Weasis vs Horos or MicroDicom?
Horos is a free alternative for Mac users only. MicroDicom is a Windows viewer; Weasis covers all three desktop platforms.
Last checked against official sources: 26 September 2026 (developer website: weasis.org). Versions and licence terms change — confirm on the developer's site before deploying in a clinic.
