# A DICOM viewer for your Mac, nothing to install

> Open DICOM files, discs and ZIPs on a Mac in Safari, Chrome or Firefox — nothing to install. Plus the MesDICOM Mac app, and how it compares with Horos.

Open DICOM files, a disc, a folder or a ZIP in Safari, Chrome, Edge or Firefox on your Mac. Free, no account, and your scans aren't uploaded — your Mac's browser opens them.

Open your scans here: https://mesdicom.com/dicom-viewer-mac/ — or at https://mesdicom.com/

On a Mac you don't need to install a DICOM viewer to look at a scan. Open this page in Safari, Chrome, Edge or Firefox, click **Open a disc or folder…** or **Open files or a ZIP…**, and MesDICOM shows the images in the browser tab — free, with nothing uploaded.

## How do I open DICOM files on a Mac?

1. **A disc or USB stick:** click **Open a disc or folder…** and choose the disc or stick in the Finder dialog, or drag its icon from the desktop onto this page.
2. **A folder or a ZIP:** choose it with the buttons above, or drag it from Finder onto the page.
3. **Single files:** choose them with **Open files or a ZIP…**. Files without a .dcm extension open too.

If the disc came with a Windows viewer program, ignore it. MesDICOM reads the images directly. More: [opening a CT or MRI disc](https://mesdicom.com/open-dicom-cd/).

## What can it do?

Scroll through series, adjust brightness and contrast with 30 window presets, zoom, rotate and flip, measure lengths and angles, play cine, look at a CT or MR series in three planes and in 3D, read every DICOM tag, and save an image as a PNG. **Save to Library** keeps a study in this browser for next time.

## Web or app: which should I use on a Mac?

| | MesDICOM on the web | MesDICOM for Mac |
|---|---|---|
| Install | Nothing | From the App Store, macOS 14.6 or later |
| Price | Free | Free to download; MesDICOM Pro (subscription) for 3D, an unlimited library and more |
| Opens | DICOM files, folders, discs, ZIP | The same, plus RAR, 7-Zip and ISO in the app |
| Keeps studies | In this browser, when you save one | In the app's library |
| Also on | Any computer with a browser | iPhone and iPad, from the same App Store listing |

The web version is the quickest way to look at a scan once. The app suits you if you open scans often or receive RAR and ISO files.

## How does it compare with other free Mac viewers?

- **Horos** is a free, open-source medical image viewer for the Mac (LGPL-3.0), installed as a desktop app.
- **Weasis** is free and open source and runs on macOS, Windows and Linux as a desktop application.
- **Windows-only viewers** such as RadiAnt and MicroDicom don't run natively on a Mac; their makers point to Wine or CrossOver.

MesDICOM on the web is for opening your own scans without installing anything.

MesDICOM is for viewing and reference only — not intended for diagnosis or treatment decisions.

## Questions

### Does it work on Apple silicon and Intel Macs?

Yes. It runs in the browser, so any Mac with a recent Safari, Chrome, Edge or Firefox works. 3D needs WebGL 2, which current Macs have.

### My Mac has no disc drive. How do I open a hospital CD?

Use an external USB DVD drive, or have the disc copied to a USB stick or sent as a ZIP. Then open it here the same way.

### The disc says it is for Windows. Will it open on a Mac?

Yes. The images are DICOM files, which don't depend on the computer. Only the viewer program on the disc is for Windows, and you don't need it.

### Is there a MesDICOM app for Mac?

Yes, on the App Store, for macOS 14.6 or later. It is free to download; MesDICOM Pro, a subscription, adds features such as 3D and an unlimited library.

## Related guides

- [DICOM viewer for Windows](https://mesdicom.com/dicom-viewer-windows/index.html.md): Open DICOM files, hospital discs and ZIPs on Windows 10 or 11 in Chrome, Edge or Firefox. Nothing to install, no admin rights, nothing uploaded. Free.
- [Open a CT or MRI disc](https://mesdicom.com/open-dicom-cd/index.html.md): Got your scan on a CD or DVD from the hospital? Open the DICOM images in your browser on Windows or Mac. No viewer program, no upload, free.
- [MRI viewer](https://mesdicom.com/mri-viewer/index.html.md): View your MRI scan online, in your browser. Open the disc, folder or ZIP from the hospital, scroll every series, see three planes and 3D. Free, nothing uploaded.

Updated October 24, 2026. For viewing and reference only — not intended for diagnosis or treatment decisions.