If you are already running macOS Catalina or a newer version, you can use the built-in command-line tool to pull a fresh copy directly from Apple’s servers. Open (found in Applications > Utilities).
Running older apps that are incompatible with newer macOS versions. Where to Securely Download macOS High Sierra 10.13.6 DMG macos high sierra 10136 dmg new
Release the key when you see the Startup Manager screen showing available bootable drives. If you are already running macOS Catalina or
Apple still provides this installer via the softwareupdate terminal command or via a link to the legacy InstallOS.dmg . As of 2026, the official "new" version is the 10.13.6 Security Update 2020-006 combo. macos high sierra 10136 dmg new