2 Easy Ways to Make a DMG File on macOS

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Easily create disk image using Disk Utility or a third-party app

Written by Megaera Lorenz, PhD

Last Updated: January 13, 2026 Fact Checked

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• Creating a DMG File Manually
|
• Downloading a DMG Application
|
• FAQ
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• Video
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• Tips

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One way to store or group files on a Mac is to create a disk image (DMG). A disk image is a file which has the properties of a separate hard drive or CD and allows for greater password protection and compression. To make a DMG file on a Mac, open the Disk Utility app and select New Image. We’ll also explain how to make a disk image using a third-party app.

Manually Creating a DMG File

1. Open Disk Utility.
2. Select File > New Image.
3. Choose Blank Image, Image from Folder, or Image from [drive name], depending on whether you want to create a DMG from scratch or from a folder or disk.
4. Set a name and save location for your disk image.
5. Choose your file system format, disk size, encryption type, and image format.
6. Click Save > Done.
7. Add files to the disk image (if you didn’t already create it from an existing folder or drive).

Steps

Section 1 of 2:

Creating a DMG File Manually

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1. 
   1
   Create a New Folder for your files. To do this, Ctrl-click or right-click on your desktop or wherever you want to put the folder, then select New Folder from the context menu. Place the files you would like in your disk image into this new folder for easy access later in the process.

   • If you want to make a blank disk image and then add files to it, you can skip this step.
   • Make note of the size of the file(s) you plan to add to your disk image. This will affect things like which format to use when creating the DMG.
2. 
   2
   Open the Disk Utility application. Go to Applications and then Utilities. Double-click Disk Utility. You can also use the

   

   Spotlight search tool in the menu bar at the top of your screen to search for and open Disk Utility.
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3. 
   3
   Select New Image from the File menu. Click File in the menu bar at the top of the screen, then select New Image > Blank Image or Image from Folder.

   • If you select Image from Folder, use the file browser to select your folder, then click Choose.
   • If you have an external disk attached, you also have the option to select Image from [drive name].
4. 
   4
   Choose a name, size, and format for your disk image. Next, you will see several options for creating your DMG. The menu will vary depending on whether you are creating a blank disk or creating a disk from a folder or drive.

   • If you’re creating a blank DMG, give your disk image a name, specify the size of the file, and choose a file system format. You can also add encryption if you want your disk image to be password-protected. Finally, choose an image format (which is separate from the file system format).
     • Image format options include RAW, UDSB, ASIF, and DVD/CD Master. If you’re not sure which one to choose, read more about these image formats here.
     • If you encrypt your disk, you’ll be asked to create a password for it. Store the password somewhere safe in case you forget.
   • If you’re creating a DMG from a folder or disk, you’ll only see the option to add a file name, add encryption, and choose an image format.
   • Select a save location for your disk image using the Where dropdown.
5. 
   5
   Click Save and Done. Your new disk image will be created and saved in your selected location.
6. 
   6
   Fill your newly created disk. If you created a blank disk and/or chose a writable format, you can add more files to your disk image. Simply select the files you want and drag them to the DMG file.
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Section 2 of 2:

Downloading a DMG Application

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1. 
   1
   Identify the application that's right for you. Manually creating DMG files with Disk Utility is extremely simple, but if you still feel that you would like to explore the option of downloading a third-party DMG application, research the different apps out there and compare their ratings and customer reviews. There are a few options out there that have helped to make the process of creating a DMG File much simpler. If you choose to download a DMG application, some popular options are iDMG and DropDMG. In this tutorial, DropDMG will be highlighted but the other apps will work similarly.
2. 
   2
   Download and launch the app. Drag the application into your "Applications" folder and then double-click it. Once it has launched, press the eject icon next to the app.
3. 
   3
   Grant the app full disk and automation access. Apps like DropDMG need full disk access to create disk images. To grant it:

   • Go to
     
     Apple menu > System Settings > Privacy & Security > Full Disk Access.
   • Toggle on the switch next to DropDMG (or your chosen DMG creation app).
     • If you don’t see DropDMG in the list, click the + icon at the bottom of the window and select it from your Applications folder. You might need to quit and reopen System Settings before it appears in the list.
   • Enter your administrator password or use TouchID to authenticate when prompted.
   • Next, grant automation access. Go to
     
     Apple menu > System Settings > Privacy & Security > Automation. Expand DropDMG and toggle on any switches underneath it.
4. 
   4
   Create your DMG File. DropDMG automatically converts files into disk images. All you have to do it drag and drop your files into the app and DropDMG will do the rest.

   • You can adjust the settings in DropDMG to change things like the file system format, encryption settings, and disk image format. To do so, click the gear icon at the top of the app window and select Configurations. Once you’ve created a configuration, you can choose it from the Configuration dropdown at the top of the main window.
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Common Questions: DMG File Formatting

What is a DMG file on a Mac? A DMG file is a disk image file. These files are primarily used to distribute software in macOS.

How do I create a DMG file with a password? To add a password to a DMG file, select the Encryption pop-up menu when creating the file. You can select an encryption type and set a password.

How do I convert a folder to DMG? To create a pre-existing folder to a DMG file, select File > New Image > Image from Folder in the Disk Utility menu. Navigate to the folder you want to use to create your disk image.

Video

Tips

• A .dmg file can be a very easy way to send files from one Mac to another. Any Mac can mount and access the Disk Image on their computer.
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• After you add your files to the image, you can unmount it and then click the Convert button in the toolbar. This will let you compress the image or change it to read only (or add encryption).
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• When you double-click a .dmg file, it will "mount" on the desktop. This is the only way to access or modify the contents of the Image.
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