How to Download a Full macOS High Sierra Installer App
Many Mac users who are attempting to download macOS High Sierra from the Mac App Store will find that a small 19 MB version of “Install macOS High Sierra.app” downloads to the /Applications folder of the target Mac, rather than the complete 5.2 GB Installer application for macOS High Sierra. This is annoying because it prevents a single download from being used on multiple computers, plus the small installer requires an internet connection during usage to download the rest of the High Sierra update files. Additionally, the tiny 19 MB incomplete installer prevents users from being able to create a macOS High Sierra USB installer drive or other custom update options available through the command line, like skipping the APFS update.
This tutorial will show you a workaround trick that allows Mac users to download the full macOS High Sierra “Install macOS High Sierra.app” file at 5.2 GB with the complete installer tool set and all dmg files and associated Install macOS High Sierra.app/Contents/Resources/ tools, rather than the tiny incomplete truncated installer at 19 MB.