Downloading requires different methods depending on whether you are using a Mac or a Windows PC. While Apple primarily distributes macOS through the Mac App Store , various tools and direct links can help you obtain a bootable file for fresh installations or virtual machines. 1. Official Apple Download Methods (For Mac Users)
Quick checklist before proceeding
If you already have an earlier version of High Sierra (e.g., 10.13.1) and only need to reach 10.13.6, you can download the macOS High Sierra 10.13.6 Combo Update directly from the Apple Support Downloads page.
: Installing High Sierra converts your drive to APFS format, which cannot be easily reversed.