How to Create Bootable MacOS Installation ISO

Things You Will need

• An existing MacOS Device or VM
• 30-40 GB of free disk space

Creating the Bootable .iso

1. Download the MacOS install from the Mac App Store
   NOTE: the easiest way to find them is to use a search engine, for example:
   macos monterey site:apps.apple.com
2. Click the Get button
3. Wait for Software Update to find the update
4. When prompted, click Download
5. Wait for the download to complete
6. Once the download completes, quit the installation if its starts
7. Start LaunchPad from the dock
8. Search terminal > Click Terminal to launch it
9. Run the following commands in terminal, altering the MacOS Installer name as needed
   # create temporary disk image, make sure its larger than the downloaded installer
   hdiutil create -o /tmp/macOS -size 15000m -volname macOS -layout SPUD -fs HFS+J
   # mount the temporary disk image
   hdiutil attach /tmp/macOS.dmg -noverify -mountpoint /Volumes/macOSISO
   # use createinstallationmedia utility to copy files
   sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/macOSISO --nointeraction
   # unmount the temporary disk image, alter the OS name as needed
   hdiutil detach -force /Volumes/Install\ macOS\ Monterey
   # convert the disk image to .iso
   hdiutil convert /tmp/macOS.dmg -format UDTO -o ~/Desktop/macOS.cdr
   # change the extension from .cdr to .iso
   mv ~/Desktop/macOS.cdr ~/Desktop/macOS.iso