---
title: ".dmg file — what it is and how to open it"
description: "A .dmg file is an Apple Disk Image. How Mac software is distributed — a disk image you mount and drag an app out of. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/dmg/
site: "At One Place"
---

# .dmg files

**.dmg file: Apple Disk Image**

How Mac software is distributed — a disk image you mount and drag an app out of.

## What opens a .dmg file

- **Windows:** 7-Zip (to inspect contents only)
- **macOS:** DiskImageMounter (built in), Disk Utility (built in)
- **Linux:** 7z x (p7zip, to inspect contents only), dmg2img

## What a .dmg file is

DMG is a macOS disk image, often compressed and sometimes encrypted, that mounts as a virtual drive when you double-click it. The convention is to drag the app inside to your Applications folder and then eject the image. On Windows, 7-Zip can list and extract the contents, but Mac applications will not run there, so extracting one is only useful for retrieving non-Mac files inside.

## Converting it

A .dmg file is commonly converted to .iso, .img or .zip. It is a binary format, so a text editor will show unreadable characters rather than its contents.

## Details

- **Extension:** .dmg
- **Full name:** Apple Disk Image
- **Category:** Disk images
- **MIME type:** application/x-apple-diskimage
- **Created by:** Apple
- **Format:** Binary

## Common questions

### How do I open a .dmg file?

On Windows use 7-Zip (to inspect contents only); on macOS use DiskImageMounter (built in); on Linux use 7z x (p7zip, to inspect contents only). How Mac software is distributed — a disk image you mount and drag an app out of.

### What is a .dmg file?

Apple Disk Image. DMG is a macOS disk image, often compressed and sometimes encrypted, that mounts as a virtual drive when you double-click it. The convention is to drag the app inside to your Applications folder and then eject the image.

### Can I convert a .dmg file?

Yes. It is usually converted to .iso, .img or .zip, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.iso — ISO Disc Image](https://atoneplace.net/file/iso/)
- [.vmdk — Virtual Machine Disk](https://atoneplace.net/file/vmdk/)
- [.cue — Cue Sheet](https://atoneplace.net/file/cue/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)