Use the ‘createinstallmedia’ command in Terminal

  1. After downloading the installer, connect your Mac to the USB flash drive or other volume that will be used as the bootable installer. Make sure that it has at least 12GB of available storage.
  2. Open Terminal, which is in the Utilities folder of your Applications folder.
  3. Type or paste one of the following commands in Terminal. These assume that the installer is still in your Applications folder, and the name of your volume is MyVolume. If it’s named differently, replace MyVolume accordingly.

    High Sierra:

    sudo /Applications/Install\ macOS\ High\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ High\


    sudo /Applications/Install\ macOS\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\

    El Capitan:

    sudo /Applications/Install\ OS\ X\ El\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\


    sudo /Applications/Install\ OS\ X\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\


    sudo /Applications/Install\ OS\ X\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\
  4. Press Return after typing the command.
  5. When prompted, type your administrator password and press Return again. Terminal doesn’t show any characters as you type your password.
  6. When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created.
  7. Quit Terminal when done.