The File Extensions Database

.DMG File Extension

  • Developer by: Apple
  • Category: Disk Image Files
  • Format: Binary

What is an .DMG file?

.DMG is Mac OS X Disk Image

A DMG file is a mountable disk image created in Mac OS X. It contains raw block data typically compressed and sometimes encrypted. DMG files are commonly used for OS X software installers that are downloaded from the Internet and mounts a virtual disk on the desktop when opened.

The DMG format replaces the older .IMG file format used in Mac OS Classic. DMG disk images can be opened using the Apple Disk Utility that is bundled with Mac OS X on Apple computers.

DMG files are Mac-specific and are not intended for use in Windows. However, Windows Daemon Tools may be able to mount virtual drives from some DMG image files. Other utilities may also be able to convert DMG files to a format that can be recognized by Windows.

Programs that open Mac OS X Disk Image
File Viewer Plus
Catacombae HFSExplorer
Reincubate DMG Extractor
Apple Disk Utility
Roxio Toast 17
Incredible Bee Archiver
Catacombae HFSExplorer
Catacombae HFSExplorer

How to solve problems with DMG files

  • Associate the DMG file extension with the correct application. On :
    Windows: Right click on any DMG file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.DMG files". Mac: Right click (or Ctrl-click) the DMG file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .DMG is Mac OS X Disk Image. Because only the current version supports the latest DMG file format. Search, therefore, e.g. on the Apple manufacturer website after an available .DMG is Mac OS X Disk Image update.
  • To make sure that your DMG file is not corrupted or virus-infected, get the file again and scan it with antivirus software.