How to Open a DMG File on Mac (and What to Do on Windows)
A .dmg file is a macOS disk image. It works like a virtual disk that contains a Mac installer or application bundle.
On a Mac, double-click the .dmg to mount it, then drag the app to your Applications folder. On Windows, the .dmg almost always contains Mac software that will not run. Download the Windows version of the software instead.
So the right answer depends entirely on which operating system you are on. Most people landing here from Windows need to stop and read the Windows section first, because opening the .dmg is not actually the goal.
On a Mac (the normal case)
Mac is where .dmg files are designed to be used. The process is straightforward.
- Double-click the .dmg file. macOS mounts it and a window opens, showing the contents, usually the application icon and a shortcut to your Applications folder.
- Drag the app icon into the Applications folder. This copies the application to the standard install location.
- Eject the disk image. Drag the mounted disk from your desktop to the Trash (the icon changes to an Eject symbol), or right-click and choose Eject.
You can now open the app from your Applications folder or Launchpad. The .dmg itself is the installer, not the app. Once you have dragged the app to Applications, you do not need the .dmg anymore.
Only download .dmg files from the official website of the software you are installing. A .dmg from an unofficial source can contain modified or malicious software.
Only use official sources. A .dmg file runs code with your user permissions as soon as you open the app inside it. Download installers only from the developer’s official site, not from third-party download hubs.
On Windows (the honest answer)
Most searches for “how to open .dmg” come from Windows. The honest answer may not be what you want to hear.
A .dmg file almost always contains Mac software that cannot run on Windows. The app inside is compiled for macOS. Extracting it does nothing useful on a Windows machine.
There are two situations where this comes up.
If you want the software: go to the maker’s website and look for a Windows download. Most apps offer a separate Windows installer, usually a .exe file. The .dmg version exists for Mac users only.
If you only need to pull files out (for example, documents or images bundled inside the .dmg), 7-Zip can sometimes open a .dmg as an archive. Any application inside will still not run on Windows. This is rarely the right path.
Not sure what extension you are looking at? Here is how to show file extensions in Windows so you can confirm before trying to open anything.
Why Windows cannot run what is inside a .dmg
A .dmg is a container format, similar to other disk image types. You may have seen a BIN file used in a similar way for disc images. The .dmg format is specific to Apple. Executables inside are compiled for macOS hardware.
Windows uses its own executable format (.exe and .msi). The two are not interchangeable. A Mac app inside a .dmg is not a “blocked” program on Windows. It is simply a file type that Windows has no instruction set for.
The only real fix is to find the Windows build of the software.
Frequently asked questions
Quick answers to common .dmg questions.
Can I open a .dmg file on Windows 10 or Windows 11?
You can attempt to extract the contents using 7-Zip, but any Mac application inside will not run on Windows. For software, find the Windows installer on the maker’s site.
What program opens .dmg files on a Mac?
macOS opens .dmg files natively with no extra software needed. Double-clicking mounts the disk image automatically.
Is a .dmg file safe to open?
A .dmg from the official software developer is safe. A .dmg from an unknown or third-party site carries real risk. Always download from the official source.
Do I need to keep the .dmg after installing?
No. Once you have dragged the application to your Applications folder and ejected the disk image, you can delete the .dmg file. The app is already installed.
Why does my .dmg say it cannot be opened because the developer cannot be verified?
macOS Gatekeeper may block a .dmg from an unrecognized developer. You can right-click the file and choose Open to bypass the warning for software you trust. Do not do this for software from unknown sources.
