Create a macOS bootable USB installer from a .dmg

What is a DMG file?

Creating a bootable macOS USB installer from a file is a multi-step process that varies depending on whether you are using a Mac or a Windows PC. If you are starting with a DMG file downloaded from Apple (like El Capitan or Yosemite), you must first extract the actual installer application before you can create the bootable drive. Apple Support Community Method 1: On macOS (Recommended) Apple's official method uses a command-line tool called createinstallmedia Extract the Installer : Double-click the file to mount it. Inside, you will usually find a

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Browse for your macOS DMG file and click . The flashing process may take 10–30 minutes depending on your USB speed. Method 2: On a Mac (The Official Apple Method) Super User Create a bootable USB drive from a DMG file on Windows

If your DMG contains a macOS installer app (like Install macOS Monterey.app ), you typically mount the DMG and use the built-in createinstallmedia utility.