sudo date 0101010119 Run the installer, then reboot and fix the date. Have an old Mac you’re keeping alive with High Sierra? Drop a comment below—I’d love to hear your story.

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB (Replace MyUSB with your USB drive’s name.) For daily use? No. It no longer receives security updates. Browsers like Chrome and Firefox have dropped support.

macOS High Sierra (10.13) was released in 2017. While it has long been superseded by Catalina, Big Sur, and Sonoma, many users still need it—either to run legacy 32-bit apps (the last macOS that fully supports them) or to breathe life into older Macs.

Absolutely. Just keep it off the internet or behind a strict firewall. Final tip If the installer refuses to run because of an expired certificate, set your Mac’s date back to 2019 before launching the installer: