How to create a bootable installer for macOS

You tin use an external drive or secondary book as a startup deejay from which to install the Mac operating arrangement.

These advanced steps are primarily for organisation administrators and others who are familiar with the command line. You don't demand a bootable installer to upgrade macOS or reinstall macOS, merely information technology can exist useful when you want to install on multiple computers without downloading the installer each fourth dimension.

What y'all need to create a bootable installer

  • A USB wink drive or other secondary volume formatted every bit Mac Bone Extended, with at least 14GB of available storage
  • A downloaded installer for macOS Monterey, Big Sur, Catalina, Mojave, High Sierra, or El Capitan

Download macOS

The installer for macOS Monterey,macOS Big Sur,macOS Catalina,macOS Mojave, ormacOS High Sierra downloads to your Applications folder as an app named Install macOS [version proper name]. If the installer opens subsequently downloading, quit it without continuing installation. To get the correct installer:

  • Download on a Mac that is compatible with that version of macOS.
  • Download on a Mac that is using macOS Sierra 10.12.v or later, or Bone Ten El Capitan 10.11.vi.
  • Enterprise administrators: Download from Apple, not a locally hosted software-update server.

The installer for OS Ten El Capitan downloads to your Downloads folder as a disk paradigm named InstallMacOSX.dmg. To go the installer:

  • Download using Safari, and open up the deejay paradigm on a Mac that is uniform with Os Ten El Capitan.
  • Inside the disk paradigm is an installer named InstallMacOSX.pkg. Information technology installs an app named Install OS X El Capitan into your Applications binder. You volition create the bootable installer from this app, not from the disk prototype or .pkg installer.

Apply the 'createinstallmedia' command in Terminal

  1. Connect the USB wink bulldoze or other volume that you lot're using for the bootable installer.
  2. Open up Final, which is in the Utilities binder of your Applications folder.
  3. Type or paste one of the following commands in Terminal. These presume that the installer is in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a dissimilar name, replace MyVolume  in these commands with the name of your volume.

Monterey:*

sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume              

Big Sur:*

sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resource/createinstallmedia --volume /Volumes/MyVolume              

Catalina:*

sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume              

Mojave:*

sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume              

High Sierra:*

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --book /Volumes/MyVolume              

El Capitan:

sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume                --applicationpath /Applications/Install\ OS\ Ten\ El\ Capitan.app              

* If your Mac is using macOS Sierra or earlier, include the--applicationpath argument and installer path, like to the way this is done in the command for El Capitan.