What is a DMG (.dmg) file?
A DMG or “.dmg” file is a disk image format commonly used by the macOS operating system, the equivalent of an “.iso” file for Windows. It is used to install downloaded applications on the system by double-clicking the icon.
Disk Image files serve as virtual disks that you can mount, and are used for distributing and installing software and media. They have a similar role to ISO files on other systems. Originally, Apple created disk image formats because application files could not be reliably transmitted over networks that were not Mac-speific, like the Internet. In 2001, Apple designed a DMG file format called Universal Disk Image Format (UDIF), which is easily transferred over the Internet.
How to open a DMG file on macOS
Opening a DMG file on macOS is easy, and the following guides will show you how to do it with various programs.
You can open a DMG file on macOS using the following programs:
Apple Disk Utility (included in the operating system)
How to open a DMG file on Windows 7/8/10
Opening a DMG file on Windows (7/8/10) is nothing complicated, and the following guides will show you how to do it with various programs.
A good program to use for opening DMG files on Windows is a freeware software called 7-Zip.
Being a freeware means you can download it for free from the official website over at https://www.7-zip.org/ , and with it being one of the most popular and widely used programs for extracting compressed files – such as ZIP, RAR, ISO and WIM files – it seems like the most straightforward option for extracting the contents of your DMG file to a specific file folder.
Here is a quick guide on how to download, install and use 7-Zip to extract a DMG file using 7-Zip:
1. Download the installation file, either from the official website at https://www.7-zip.org/ or from a different reliable source. Look for whichever version of the program you need, and download it by clicking the blue “Download” button on the left
2. Once downloaded, navigate to the downloaded installation file and run it by double-clicking the icon. The installation wizard will appear, simply select a folder where you would like your 7-Zip installed and click Install. After a very short period your 7-Zip will now be installed and ready to use
3. After successfully installing 7-Zip, you will need to find the DMG file you are looking to extract. Once navigated to, right click the DMG file and mouse the 7-Zip menu to load your extraction options.
You can either select the “Extract files… ” or “Extract Here” based on what your preferences are.
4. The “Extract files… ” option will open up a menu for you to select what file directory you want your DMG file extracted to, whereas the “Extract Here” option simply extracts the compressed contents of the file into the same folder the DMG file is in. Click on whichever option you find most convenient.
5. After selecting an extraction option, your extraction will begin and the extraction window will appear. On this window you can pause your extraction, see the progress of your extraction as well as the elapsed and remaining time, extraction speed, etc. When this screen disappears it means your file has been fully extracted and is ready for use.
The speed at which your file extracts is highly dependant on the size of the DMG file itself, as well as the capabilites of your hardware, such as your RAM speed. Depending on what was inside your DMG file, you can now use the items compressed inside.
Aside from 7-Zip, there are other programs that can extract a DMG file on Windows (7/8/10) systems, such as the following:
DMG Extractor https://reincubate.com/dmg-extractor/
Note: Please keep in mind that although you can use programs like 7-Zip and DMG Extractor to extract the DMG file, whether you will be able to use the file depends on what is compressed inside the DMG file.
If the file contains items that are likely in a format compatible with Windows, such as videos or images, you will be perfectly fine extracting and opening those items.
However if the DMG file contains an executable file that installs a software, you will not be able to actually run the executable file compressed inside, like you would win an application designed for the Windows operating system.
To install your desired application on Windows, you will need to find and download the Windows version of the program, as DMG files are primarily designed for Mac operating systems.
You can open a DMG file on Linux using the following programs:
How to convert a DMG file
Using https://cloudconvert.com/dmg-converter we can convert it to the following formats:
- DMG to 7Z
- DMG to RAR
- DMG to TAR
- DMG to TAR.BZ2
- DMG to TAR.GZ
- DMG to ZIP
To use https://cloudconvert.com/dmg-converter follow these steps:
1. On the website, select which format you are converting from what what format you would like to convert your file to.
2. Click Select File and locate your file on your computer.
3. Once you have located the file, click Open.
4. After the file has been properly selected, click Convert.
After a short process, you will be able to download your file in its new format by clicking the Download button on the bottom right.
DMG file still not opening?
If you can’t open a DMG file with the help of the applications listed in this guide, it is very possible that the file in question is a different file type, and you’ve mistaken the extension for something else.
This can happen with various other similar looking extensions, such as the GMD and DGML extensions.
The former extensions is a file type associated with text display in Nintendo 3DS games, such as dialogue that appears during the game and the appearance of the dialogue.
The latter extension is used in files related to Visual Studio, a software development application.
Neither of these formats are related to the DMG file, so if your file happens to be one of the other aforementioned extensions, you will need different applications to open and view those files.
A common issue with DMG files is the “DMG not verified” error message, which stops users from opening and mounting the file and installing the software. This error can occur due to several reasons, but the most common ones are an incomplete download of the DMG file, or a corrupt file.
Some symptoms of an such errors could include:
1. The entire operating system feeling sluggish or slow
2. Programs frequently freezing or crashing
3. Lost data that is no longer accessible
4. Damaged or corrupted OS files
Causes of these symptoms could be a number of different situations, such as: accidental system file deletion, the system suddenly shutting down due to external factors such as power outages, virus infestations, applications and programs that have been incorrectly installed, software and/or hardware issues.
The DMG or .dmg file format is the most commonly used file format for the purpose of distrubuting and installing applications on the MacOS operating system.
The disk image can be mounted using Apple Disk Utility included in the operating system, or other programs. Once mounted, double clicking the program icon will run the application.
It can be converted to a 7z or ISO file for use on a Windows operating system.