Create Mac Os X Bootable Usb Installer From Dmg 【2026 Update】

Creating a bootable macOS USB installer from a DMG file depends on whether you are using a Mac or a Windows PC. On a Mac, the standard method involves extracting the "Install macOS" app from the DMG and using the native createinstallmedia

4. Verify the Bootable Installer

• Once the process completes, your USB drive will be a bootable installer for macOS.
• To verify, restart your Mac, hold down the Option (⌥) key, and select the USB drive as your startup disk.

• Use /dev/rdiskN (raw device) for faster write; replace rdiskN with the raw device (e.g., /dev/rdisk2).
• If you used the original .dmg directly and it's writeable, set if=/path/to/installer.dmg instead.

Eject when done

diskutil eject /dev/disk2