When it’s time to install a new version of macOS or download a new update, nearly everyone turns to the Mac App Store to start the process. While the App Store makes OS installations easy and relatively painless, it doesn’t always work—and it might be time to turn to Terminal (and a little creativity) instead.
Terminal is especially helpful if you’re trying to install older versions of macOS or OS X, many of which are technically accessible from the Mac App Store but will be listed as “unavailable” when you try to download. You might not be able to grab them this way, but Terminal can do the legwork for you.
How to use Terminal to download macOS updates and installation files
We’ll focus on two specific commands in this guide: One that downloads the latest macOS update, and another that will let you download older macOS or OS X build, as detailed by 512 Pixels and the JAMF open source community on GitHub. Doing so requires a bit more work than simply clicking through the App Store, but don’t worry—terminal commands may look daunting if you’re new to them, but the ones we’ll be using are simple to execute. Here’s how:
Begin opening macOS Catalina’s Terminal by going to Finder > Applications > Utilities > Terminal.
Type one of the following commands into Terminal:
To download the latest macOS update , type:
To download older builds of macOS, type:
softwareupdate —fetch-full-installer [build number](for example: “softwareupdate —fetch-full-installer 10.14.5″)
Press the “Return/Enter” key to perform the command.
The installation file will download to your Mac’s Applications folder. Open the file to begin the installation, and then follow the on-screen instructions to complete the update (or rollback).
Bear in mind that not all versions of macOS or OS X can be downloaded this way, and some versions are only compatible with certain Mac hardware. Still, this should work just fine for snagging the latest macOS updates, and you should be able to download several older macOS and OS X releases (potentially as far back as OS X Yosemite).
For advanced users, it’s also worth mentioning these aren’t the only Terminal commands you can use to change or update your Mac’s OS, and you can find plenty more to play with on the JAMF community Github page.