If you want to know how to create a bootable USB to install macOS Big Sur, Catalina, Mojave, and High Sierra, then this post is for you. You can use this bootable USB macOS installer to perform a clean install of macOS, install macOS from USB on a separate volume of your Mac drive, or in case your Mac encounters OS issues. If you plan to install macOS on multiple Mac systems and don’t want to download the installer multiple times, then you can create a bootable installer.
