RadDream comes first because this guide is written by 5C for hospitals and reading rooms. Each other profile says what the product is best at and what to watch for.
RadDream
5C Network, Bengaluru (India) Web viewer inside a reporting platform · Any web browser, nothing to install
RadDream is 5C Network's radiology viewer, built in-house by 5C's engineering team. Since October 2026 it has been the viewer for every study on the 5C platform: 5C's 400+ specialist radiologists read in it every day, on a platform that handles 20,000+ scans a day. It is engineered for speed. What sets it apart is what sits around the image: Bionic AI findings appear on the image with a draft impression beside it, and the report editor is one click away. It supports X-ray, CT, MRI, mammography, PET-CT and nuclear medicine. Disclosure: this is our product.
- ✓Bionic AI findings on the image, draft impression beside it, report editor one click away
- ✓MPR, curved MPR, 3D volume rendering, MIP and PET-CT fusion in the browser
- ✓Hanging protocols, linked series, prior comparison, keyboard shortcuts
- ✓Share links for referring doctors; images can be restored from the viewer after a link expires
- Cost
- Comes with 5C's platform (5C reporting and 5C SuperPACS). Not sold standalone, not free to download; no published price
- Best for
- Hospitals and diagnostic centers that want the viewer, AI and reporting in one screen
Worth knowing: It is not a standalone download, not free and not white-label. You get it with 5C's reporting or 5C SuperPACS. If you only need to open a study on your own computer, pick one of the free viewers below.
RadDream, 5C's web DICOM viewer RadDream vs MedDream 5C SuperPACS
MedDream DICOM Viewer
MedDream, UAB (Lithuania) White-label web viewer (HTML5, zero-footprint) · Web browser on desktop, tablet and mobile; server on-premise or cloud (Docker, Windows, Linux packages)
MedDream describes its viewer as web-based, vendor-neutral, white-label and zero-footprint, built to be licensed and integrated into someone else's PACS, VNA, RIS or portal. Per its product page it is FDA cleared for diagnostic use, including mammographic images, and CE Class IIb certified, and it states 660+ B2B partners, 3,800+ server installations and 85+ countries, with the viewer "engineered for 1,000+ concurrent users".
- ✓Full white-label rebranding; URL integration, Communication API and Viewport API (React/Angular)
- ✓Multi-specialty: radiology, cardiology, ultrasound, dentistry, ophthalmology, digital pathology and more
- ✓MPR, MIP, 3D, segmentation, hanging protocols; "AI & CAD ready" for third-party algorithms
- ✓On-premise or AWS, Google Cloud, Azure and Alibaba Cloud deployments
- Cost
- Commercial license; sold to software vendors, OEMs, integrators, resellers and providers
- Best for
- Software vendors and OEMs embedding a certified viewer in their own product
Worth knowing: It is a component, not a finished reading room: AI comes from third-party algorithms you connect, and reporting from your RIS. Pricing is not published.
Sources (vendor's own, read 26 October 2026): meddream.com/products/meddream-dicom-viewer
OHIF Viewer
Open Health Imaging Foundation, a program of Massachusetts General Hospital, developed with Radical Imaging Open-source web viewer (zero-footprint) · Runs entirely in the browser; you host it
OHIF is the best-known open-source web DICOM viewer. Per its site it is a program of Massachusetts General Hospital, developed in collaboration with Radical Imaging, released under the MIT license and running entirely in the browser. It is designed as an extensible platform: extensions and modes let teams build their own workflows, and it connects to any image archive that speaks DICOMweb.
- ✓MIT license: free to use, modify and ship inside commercial products
- ✓Works out of the box with archives that support DICOMweb
- ✓GPU-accelerated visualization, PET/CT, segmentation, measurement tracking
- ✓Plugin framework for task-based workflow "modes"
- Cost
- Free, open source (MIT license)
- Best for
- Developers and research teams building a web viewer on DICOMweb
Worth knowing: OHIF's own FAQ says it is not FDA cleared or CE marked and does not by itself meet HIPAA criteria; compliance is the deployer's responsibility. You also need an archive and engineers to host and maintain it.
Sources (vendor's own, read 26 October 2026): ohif.org · docs.ohif.org · docs.ohif.org/faq
RadiAnt DICOM Viewer
Medixant, Poznan (Poland) Desktop viewer · Windows (7 to 11)
RadiAnt is made by Medixant, a small, privately funded company in Poznan, Poland. It is a Windows desktop viewer known for simplicity and speed, with MPR, 3D volume rendering and PET-CT fusion. RadiAnt is often described as free, but its own site is more precise: there is a free trial that includes every feature and expires after a set period, and continued use needs a paid subscription. Its pricing page lists one PC for one year at 39 EUR, with longer plans and volume discounts.
- ✓Small installer; "quick as lightning" per Medixant, with 64-bit support for large studies
- ✓MPR, 3D volume rendering and PET-CT fusion
- ✓Same features in the trial and the paid version
- ✓CD/DVD edition with a permanent license for burning studies to disc
- Cost
- Free trial with all features, which expires; paid subscription per PC (39 EUR for one year on its pricing page, October 2026)
- Best for
- Individual doctors who want a fast, polished Windows viewer at low cost
Worth knowing: Its license terms say it is not certified as a medical product and must not be used to make diagnostic or therapeutic decisions or to interpret and report studies. It is Windows-first.
Sources (vendor's own, read 26 October 2026): radiantviewer.com · radiantviewer.com/about · radiantviewer.com/products/radiant-dicom-viewer-standard · radiantviewer.com/store/pricing · radiantviewer.com/terms
Weasis
Open-source project founded by Nicolas Roduit Open-source desktop viewer with web launch · Windows, macOS and Linux; launches from web portals via weasis://
Weasis describes itself as a multifunctional, open-source DICOM viewer for both standalone and web-based use. It runs on Windows, macOS and Linux, is dual-licensed under EPL 2.0 and Apache 2.0, and its site says it is production-grade at HUG and across hospitals, trials and portals worldwide. Its weasis:// protocol lets a portal open a study in the desktop viewer with one click, which is why it often sits behind hospital web portals.
- ✓CT, MR, ultrasound, X-ray, mammography, PET, ECG, structured reports, segmentations, RT plans
- ✓3D and MPR, multi-monitor, measurements and annotations
- ✓DICOMweb and DIMSE query/retrieve
- ✓One-click launch from browsers, EHR and RIS portals with the weasis:// protocol
- Cost
- Free, open source (EPL 2.0 / Apache 2.0)
- Best for
- Hospitals and portals that want a free, cross-platform viewer they can launch from a RIS or EHR
Worth knowing: It is a desktop application that a portal launches, not a pure in-browser viewer, so each machine needs it installed. Its site makes no regulatory claim.
Sources (vendor's own, read 26 October 2026): weasis.org/en · weasis.org/en/getting-started · github.com/nroduit/Weasis
Horos
The Horos Project Open-source desktop viewer · macOS
Horos is the usual answer to "is there a free DICOM viewer for Mac?". Its GitHub repository describes it as a free, open-source medical image viewer whose goal is a fully functional, 64-bit viewer for macOS, based on OsiriX and other open-source libraries and released under LGPL-3.0.
- ✓Native 64-bit macOS application
- ✓Based on OsiriX and other open-source imaging libraries
- ✓Free under LGPL-3.0, with source on GitHub
- Cost
- Free, open source (LGPL-3.0)
- Best for
- Mac users who want a free, full-featured desktop viewer
Worth knowing: It is Mac-only. Its project website did not respond when we checked on 26 October 2026, so we relied on its GitHub repository; make no assumptions about regulatory status.
Sources (vendor's own, read 26 October 2026): github.com/horosproject/horos
PostDICOM
PostDICOM B.V. (Netherlands) Cloud PACS with web viewer and image sharing · Web browser on desktop, tablet and mobile; a local communicator app connects imaging devices
PostDICOM describes itself as a cloud PACS, a CE Mark Class IIb diagnostic viewer and a medical image sharing platform with a zero-footprint HTML5 viewer. Unusually for this category, it publishes prices: Essential at 79 EUR a month (100 GB), up to Enterprise at 499 EUR a month (2,000 GB), billed annually. It also lists ISO 27001 and ISO 13485 certification.
- ✓Cloud storage, viewer and sharing in one subscription, no local server
- ✓MPR, 3D volume rendering, MIP/MinIP, measurements and reporting
- ✓Password-protected share links and patient upload links
- ✓DICOMweb (QIDO-RS, WADO-RS, STOW-RS); API and FHIR on higher plans
- Cost
- Paid plans from 79 EUR a month billed annually (100 GB), with a 7-day trial, per its site (October 2026)
- Best for
- Small clinics that want cloud storage, a web viewer and patient sharing with published prices
Worth knowing: It is a cloud PACS, so you are choosing where your studies are stored, not only a viewer. There is a trial, not a free plan.
Sources (vendor's own, read 26 October 2026): postdicom.com
MicroDicom DICOM Viewer
MicroDicom Ltd, Sofia (Bulgaria) Desktop viewer · Windows (7 to 11); runs on a Mac only through Wine or CrossOver
MicroDicom is made by MicroDicom Ltd in Sofia, Bulgaria, in development since 2006 and, per its site, downloaded over 4 million times. It is a Windows viewer that is free for non-commercial use, with a paid license for commercial use, and it covers CT, MRI, ultrasound, X-ray and PET-CT, with MPR and 3D.
- ✓Free for personal, non-commercial use
- ✓MPR, 3D volume rendering and image fusion
- ✓PACS connectivity (C-FIND, C-MOVE, C-STORE, QIDO-RS, WADO-RS, STOW-RS)
- ✓Export to JPEG, PNG, MP4 and STL; built-in DICOM anonymizer
- Cost
- Free for non-commercial use; commercial use needs a paid license key
- Best for
- Patients and students who need a free Windows viewer to open a scan CD
Worth knowing: Its EULA says it is not certified as a medical product and must not be used to make diagnostic or therapeutic judgements. On a Mac it needs Wine or CrossOver.
Sources (vendor's own, read 26 October 2026): microdicom.com · microdicom.com/company.html · microdicom.com/eula.html · microdicom.com/microdicom-viewer-documentation/how-to-install-microdicom-dicom-viewer-on-macos.html
3D Slicer
Open-source community; the US NIH has been a major funder Open-source research platform · Windows, macOS and Linux
3D Slicer is free, open-source software for visualization, processing, segmentation, registration and analysis of medical and other 3D images. It runs on Windows, macOS and Linux under a BSD-style license, and its documentation calls it a research software platform for developing and evaluating new methods.
- ✓Segmentation, registration and analysis of 2D, 3D and 4D images
- ✓DICOM import and export, DICOMweb and DIMSE networking
- ✓Python scripting and 150+ extensions
- ✓Virtual and augmented reality support
- Cost
- Free, open source (BSD-style license)
- Best for
- Researchers doing segmentation, registration, 3D printing and surgical planning
Worth knowing: Its documentation is explicit: "3D Slicer is NOT FDA approved" and it is not approved for clinical use. Use it for research and planning, not as a reading viewer.
Sources (vendor's own, read 26 October 2026): slicer.org · slicer.readthedocs.io/en/latest/user_guide/about.html · slicer.readthedocs.io/en/latest/user_guide/getting_started.html
