What's the best free DICOM viewer for patients?#
Which free DICOM viewers should patients try first?#
- OpenMyScan (this site). Browser-based, runs on any modern computer, no install, no account, no upload. Free for everyone — see the DICOM viewer for the full feature list. Includes PNG export, ZIP share package, and compare-two-scans mode at no cost. Made specifically for patients.
- Horos (macOS). Excellent open-source clinical viewer. Free but Mac-only and clinical-looking — measurement tools, fusion, etc. If you're a Mac user comfortable with professional software, it's great. Requires install.
- RadiAnt (Windows). Trial is free, full version paid. Fast, popular with radiologists.
- Weasis (cross-platform). Java-based, open-source. Runs on anything but needs Java, which most people don't have.
- OsiriX MD / Lite (macOS). One of the oldest clinical viewers, and the project Horos was originally forked from. Powerful, but the UI is dense.
How do free DICOM viewers compare for patient use?#
| Tool | Install needed? | Upload to server? | Patient-friendly UI? | Works on school/work PC? | Free for full viewing? |
|---|---|---|---|---|---|
| OpenMyScan | No | No | Yes | Yes | Yes |
| Horos (Mac) | Yes | No | Somewhat | No | Yes |
| RadiAnt (Windows) | Yes | No | Somewhat | Maybe | Trial only |
| Weasis | Yes (Java) | No | Clinical | Unlikely | Yes |
| OsiriX Lite | Yes | No | Dense | No | Yes (limited) |
| "Online uploader" sites | No | Yes | Varies | Yes | Varies |
Why not an "upload your DICOM here" site?#
Any viewer that requires upload is storing your medical images on their servers — subject to their privacy policy, breach risk, and terms that can change. For a one-off "look at my own MRI" use case, the right default is a tool that opens files locally: OpenMyScan in your browser, or an installed viewer like Horos.
When do I need a clinical DICOM viewer?#
If you want to measure a lesion in mm, do angle / Cobb-angle measurements, print DICOM at true scale for a physical therapist, or run advanced 3D reconstruction — use Horos / RadiAnt. OpenMyScan deliberately omits those to stay simple for non-technical users.
What goes wrong when patients pick a DICOM viewer?#
- IT locked my work laptop
- Browser viewers avoid installers; if even those are blocked, use a personal device.
- I downloaded three apps and none open the CD
- Copy the DICOM folder off the disc first — many tools choke on read-only drives.
- A site promises "AI diagnosis"
- Walk away for casual browsing — automated reads are not a substitute for your doctor.
- I need to share files privately
- Sending medical files by email or general cloud accounts can expose them to third parties. Use encrypted channels or your hospital's portal when privacy matters.
Common questions#
Is OpenMyScan really free forever?
Yes, OpenMyScan is free for everyone — no paid tier, no subscription, no paywall. Every feature, including PNG export, compare, and ZIP share package, is included.
Is OpenMyScan open-source?
The viewer runs fully client-side and no data leaves your device. The site source itself is not currently published.
What about online viewers like "Jack Imaging" or similar?
Those upload your DICOM to their cloud. They're fine for second-opinion workflows where you want to share with a specific doctor, but not for local viewing.
Does this work offline?
Yes, after the first successful load. OpenMyScan caches in your browser, so you can use it on a plane or without WiFi as long as the page loaded once. Your files stay local either way.