How to open .DMG files on Mac

To open .DMG files on Mac, double-click the .dmg file in Finder to mount it (it should appear as a disk/volume).

Step-by-step instructions

  1. Double-click the .dmg file in Finder to mount it (it should appear as a disk/volume).
  2. Open the mounted volume and follow the app’s instructions (commonly: drag the app to Applications or run an included installer).
  3. When finished, eject the mounted disk image in Finder.

Alternative methods

  • Open .DMG in a browser-based viewer if desktop apps fail.
  • Try opening .DMG on Mac with a secondary app to rule out app-specific issues.
  • Convert .DMG only with trusted tools when direct opening is not possible.

Common issues

Double-clicking a DMG does nothing or shows an error (macOS)

This can happen if the download is incomplete/corrupted or if the disk image can’t be mounted by the system.

  1. Re-download the .dmg from the original source and try again.
  2. Try mounting it via Finder again; if it still fails, obtain a fresh copy or ask the publisher for an updated DMG.

DMG won’t open on Windows

Windows doesn’t natively mount Apple disk images, so you’ll need a tool that can read DMG contents.

  1. Use a Windows utility that explicitly supports DMG (for example, TransMac per its documentation).
  2. If you need to install a macOS app from the DMG, use a Mac instead—Windows can’t run macOS apps even if you extract them.

I can open the DMG but can’t use what’s inside

Many DMGs distribute macOS applications (.app bundles) or macOS installers that are not usable on Windows, Linux, iOS, or Android.

  1. Check what the DMG contains (for example, a macOS .app or installer).
  2. If it’s macOS-only software, open/install it on macOS; otherwise, look for a Windows/Linux version from the publisher.

Security note

Treat DMGs like software installers: a DMG may contain executable macOS apps or installers, so only open disk images you trust.

Back to .DMG extension page