Best Free DICOM Viewers for Mac and Windows

If you work with medical images, you already know how frustrating it can be to find a reliable DICOM viewer that doesn't cost anything.

Whether you're a chiropractor, radiologist, or anyone else who needs to open DICOM files regularly, there are solid free options out there for both Mac and Windows.

And if you prefer something you can access from any browser, a web-based DICOM viewer can be a practical choice too.

Here's what people are actually using.

For Mac users

Horos

Horos is probably the most recommended free DICOM viewer for Mac. It's full-featured, handles plain films well, and most users find it reliable for everyday clinical use.

One thing to note: the download page asks for a donation before showing the free option. The free download link is there, but it's in small text at the bottom of the page. You don't have to pay anything to use it.

A few things worth knowing about Horos:

●      It works well on older Intel Macs

●      On M1 and M2 chips, some users report slower performance, especially with MRP reconstructions

●      You may need to download an older version if you're on Apple Silicon

It's not perfect, but for most use cases, it gets the job done.

OsiriX

OsiriX has been around for a long time and shares the same open-source foundation as Horos. The free version (OsiriX Lite) is available on the App Store, though it has some limitations compared to the paid version.

If you're already familiar with Horos, OsiriX will feel very similar. They're built on the same base.

Weasis

Weasis is a cross-platform viewer that works on Mac, Windows, and Linux. It's free and open-source. Some Mac users feel it doesn't look or behave like a native Mac app, which can make it feel slightly awkward to use. But it works, and it handles DICOM files without issues.

For Windows users

RadiAnt

RadiAnt is one of the cleanest and most user-friendly DICOM viewers available for Windows. It loads images fast, has a simple interface, and supports a wide range of modalities. Many users prefer it over heavier alternatives because it doesn't require much setup.

There is a free trial version available, and the full license is reasonably priced if you end up needing more features.

Weasis

As mentioned above, Weasis works on Windows too. It's free, open-source, and handles most DICOM files without trouble. It's worth trying if you want something that runs locally without any cost.

MIPAV

MIPAV (Medical Image Processing, Analysis, and Visualization) is developed by the National Institutes of Health. It's Java-based, which means it runs on Windows, Mac, and Linux. It's free and lets you view and edit DICOM tags, which makes it useful if you ever need to correct metadata on existing images.

A cloud option worth considering: PostDICOM

If you'd rather skip the installation entirely, PostDICOM is worth a look. It's a cloud-based DICOM viewer that runs in any browser, so it works on Mac, Windows, or any other device you're on.

You upload your studies, and you can view, share, and manage them from anywhere. It's a good fit if you need to share images with colleagues or send studies to patients without the back-and-forth of physical media or large email attachments.

The free plan includes storage and basic viewing features, which is enough for many smaller practices. And because everything runs in the browser, there's no software to maintain or update on your end.

FAQ

Can I view DICOM files without installing any software?

Yes. Cloud-based options like PostDICOM let you view DICOM files directly in your browser. You upload your study, and it's accessible from any device with an internet connection.

Is it safe to use free DICOM viewers with patient data?

It depends on the software. Locally installed viewers like Horos and RadiAnt keep your data on your own machine. If you're using a cloud-based viewer, check the privacy policy carefully before uploading any patient images. Look for HIPAA compliance or GDPR coverage depending on your region.

Can I edit DICOM tags with a free viewer?

Yes. MIPAV lets you edit DICOM tags after an image has been created. This can be useful if a study was saved with incorrect metadata.

Do these viewers support all imaging modalities?

Most of the options listed here support common modalities like X-ray, CT, and MRI. If you work with less common modalities, check the documentation for the specific viewer before committing to it.