What is the of the Mac you are targeting?

hdiutil convert /tmp/HighSierra.dmg -format UDZO -o ~/Desktop/macOS_High_Sierra_10.13.6.dmg Use code with caution.

Having a physical installer is the best way to perform a "clean install" or troubleshoot a Mac that won't boot.

Even in 2026, macOS High Sierra 10.13.6 remains a vital operating system for many, particularly for maintaining older MacBook Pro, iMac, or Mac Pro machines that cannot upgrade to newer systems like macOS Sonoma or Monterey. Whether you are aiming to fix an older Mac, build a Hackintosh, or create a bootable USB installer to clean install, a full 10.13.6 DMG is essential.

High Sierra updates your Mac's firmware to recognize the newer APFS file system structure. If you are using a third-party non-Apple SSD, the firmware update may fail.