sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled Use code with caution.
Once you have your DMG file, you can create a bootable installer on a USB flash drive.
Click . Your Mac will open Software Update to fetch the complete companion file.
: A popular open-source utility that lets you choose and download specific macOS versions (including High Sierra) as a DMG or ISO. You can find it on GitHub. download macos high sierra 10.13 6 dmg file
If a Mac suffers severe drive corruption or lacks an internet connection, a local bootable installer created from a DMG bypasses internet recovery bottlenecks.
Running older 32-bit applications that are completely blocked on macOS Catalina and later.
This is a common glitch. Do not restart your computer. Simply be patient; it can take 15-45 minutes to complete. If it is truly frozen for over an hour, you may need to restart and try the installation again. sudo /Applications/Install\ macOS\ High\ Sierra
If you are on a PC and have already sourced a High Sierra DMG, you can use TransMac to "Restore with Disk Image" and create a bootable drive for a Mac.
On Macs running macOS Catalina 10.15 or later, you can download the installer directly using this command in Terminal: softwareupdate --fetch-full-installer --full-installer-version 10.13.6 2. Update vs. Full Installer
Once complete, the installer will sit in your /Applications folder as a file named Install macOS High Sierra.app . Your Mac will open Software Update to fetch
The full installer is approximately 5.2 GB . The combo update is approximately 2.49 GB .
If you double-click the DMG and nothing happens, or you see a "No mountable file systems" error, the file may be blocked by macOS's security. Try these fixes in order: