Apple typically provides older macOS versions through the App Store or direct disk image (.dmg) downloads for older machines.
You now have a clean, officially sourced macOS High Sierra 10.13.6 DMG file on your desktop. How to Create a Bootable USB Installer
: It supports many Mac models from 2009 to 2011 that cannot run newer versions like Mojave or Catalina. download macos high sierra 10.13.6 dmg mac
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/HighSierraUSB Use code with caution. Press .
Convert the sparse image to a standard read-only .dmg : hdiutil convert ~/Desktop/HighSierra.sparseimage -format UDTO -o ~/Desktop/macOS_High_Sierra_10.13.6.cdr Apple typically provides older macOS versions through the
Format your target storage drive to or Mac OS Extended inside Disk Utility if doing a clean install.
Note: If the official Apple link is dead (Apple occasionally retires them), proceed to Method 2 or 3. sudo /Applications/Install\ macOS\ High\ Sierra
: If you already have a version of High Sierra and need the 10.13.6 patch, you can download the 10.13.6 Update 10.13.6 Combo Update directly from Apple's support site. Mist Utility
If you need a DMG-like experience to install on another machine, you must convert the downloaded into a bootable USB: 16GB+ USB drive formatted as Mac OS Extended (Journaled) Run this command in Terminal:
Once you have the full Install macOS High Sierra.app in your Applications folder, you can use Apple's built-in createinstallmedia command to make a bootable USB drive. This is the preferred method for performing clean installs on multiple machines or troubleshooting failed upgrades.