Final update to High Sierra — July 9, 2018.

This yields a ready for VMs or old hardware.

You will now find a clean, bootable, official file sitting right on your Mac's desktop, ready to be used. Can You Download Pre-Made High Sierra ISO Files?

First, create a temporary blank disk image ( .dmg ) on your desktop with enough storage space to hold the installer (around 8GB):

softwareupdate --fetch-full-installer --full-installer-version 10.13.6

Are you planning to use this ISO for a or to fix an older physical Mac ? macOS High Sierra - App Store