Download the Full macOS Big Sur Installer using the Command Line
This tutorial will show you how to download the macOS Big Sur installer on your Mac. You can use it to upgrade macOS or create removable media to update a different Mac.
Step 1: Launch Terminal
Open the Terminal app by pressing Command + Space, searching for “Terminal” then pressing Return.
Step 2: Download Big Sur Installer with Software Update Utility
As of writing, the latest version of macOS Big Sur is 11.5.2, you can download it by running the following command (replace 11.5.2 with the version you want to download).
softwareupdate --fetch-full-installer --full-installer-version 11.5.2
You will notice the output of the command reads
Don’t worry, it’s not installing the update on your Mac. All it’s doing is downloading the installer to your Applications folder.
Wait for the progress to reach 100% and the output to say
Install finished successfully, then you should see the Install macOS Big Sur app appear in Applications.
You can now use the Install macOS Big Sur app to upgrade your Mac’s operating system or use it to create removable media to upgrade another Mac. Check out the following tutorials to learn how to create a bootable DVD or USB Flash Drive.