How to Open DMG Files

DMG files are Mac disk images. They are usually opened or mounted, not treated like ordinary ZIP files.

Updated for 2026. This guide favors built-in tools and reputable free utilities before paid or obscure software.

On a Mac

Double-click the DMG, wait for it to mount, and look for the window or mounted disk in Finder. Many app installers ask you to drag an app into Applications. Do not run an app unless you trust the developer.

After copying what you need, eject the mounted DMG. You can keep or delete the downloaded DMG depending on whether you need the installer again.

On Windows

A DMG is not a Windows-native package. You may be able to extract files from it with a third-party tool, but apps inside a DMG usually will not run on Windows.

If someone sends you a DMG and expects you to use it on Windows, ask for the correct file type instead of forcing a workaround.

Red flags

The DMG asks you to bypass Gatekeeper warnings.
The file came from an unofficial mirror.
The app name does not match the developer or expected product.
The instructions pressure you to install browser extensions or profiles.