Weasis review
A capable free viewer with broad DICOM connectivity, but no PACS storage.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
For imaging teams that need a desktop viewer without licensing fees, Weasis combines open-source distribution with support for Windows, macOS and Linux. It opens local DICOM studies and common non-DICOM formats, while connecting to PACS and DICOMweb archives. The viewer covers CT, MR, US, PET, SPECT, ECG and radiotherapy objects, making it suitable for small, mid-market and enterprise workflows that need review and exchange rather than centralized image management.
Its connectivity is a major strength. Weasis supports DICOM Query/Retrieve through C-FIND, C-GET, C-MOVE and WADO-URI, alongside DICOMweb QIDO-RS, WADO-RS and STOW-RS. Studies can be sent to PACS or DICOMweb servers, and the application can fit EHR, RIS and HIS workflows, including launches from web portals. For interpretation, it offers 2D manipulation and DICOM rendering, MPR, MIP and 3D volume rendering, plus measurements, annotations and pixel-region statistics. It can also display DICOM segmentation, radiotherapy objects, ECG waveforms and structured reports.
As a free, open-source desktop application, Weasis keeps entry costs low and can convert standard images, videos, PDFs and STL meshes into DICOM. Its scope is viewing, conversion and exchange: it does not provide PACS storage, so organizations need an external PACS or DICOMweb server for centralized archiving. The open-source distribution is not a certified medical device, and support is centered on documentation and community channels. Teams seeking a broad viewer for existing imaging infrastructure should consider Weasis; teams requiring built-in AI analysis, managed storage or a certified medical device should choose a product designed for those needs.
Weasis pros and cons
- Where it wins
- Broad DICOM and DICOMweb query, retrieval and sending support
- MPR, MIP, 3D rendering, measurements and annotations
- Handles segmentation, radiotherapy objects, ECG and structured reports
- Where it doesn't
- Does not provide PACS storage
- No built-in AI image-analysis tools
- Desktop deployment with docs and community support
Weasis fact sheet, pricing and score →
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