If you are using a newer Mac and need to download the installer to build a bootable drive for an older machine, you can use the command line: Open the app (found in Applications > Utilities). Type or paste the following command exactly:
The ultimate guide to downloading gives you the exact links, tools, and steps needed to upgrade or restore your older Mac safely. Why Download macOS High Sierra 10.13.6?
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/[Your USB Drive Name] download+macos+high+sierra+10136+exclusive
If you are running an older macOS version that supports direct App Store links, you can fetch the installer directly from Apple.
Once you've downloaded the Install macOS High Sierra.app or the .dmg file, you'll likely want to create a bootable USB installer for multiple or clean installations. If you are using a newer Mac and
Open your web browser and navigate to the official . Click the link for macOS High Sierra .
Open the application (found in Applications > Utilities ). Type or paste the following command exactly as shown: sudo /Applications/Install\ macOS\ High\ Sierra
You can still find the full installer through official channels, but the App Store often hides it. The "Secret" App Store Link : You can often trigger the download by visiting the Apple Support page for older macOS versions
Apple officially removes older macOS versions from the main App Store storefront over time. However, they maintain hidden "direct links" on their support servers. You do need to visit third-party "exclusive" download sites, which often bundle malware.