Once you have downloaded the installer app (usually named "Install macOS High Sierra" in your Applications folder), you can create a bootable disk image or USB drive:
Having the DMG is useless if you can’t boot from it. Most online tutorials fail because they don’t account for High Sierra’s unique APFS conversion. download macos high sierra 1012 dmg exclusive
Who should use High Sierra now
Official Apple channels (recommended)
Apple provides direct download links for older macOS versions, which must be opened in to function correctly. macOS High Sierra 10.13 Installer (via Mac App Store) macOS Sierra 10.12 DMG (Direct DMG link from Apple) System Requirements Once you have downloaded the installer app (usually