Software Update found the following full installers:

(note that the option starts with two hyphens, not an m-dash)

First list the installers available using the command Your fallback then, if you’re running Big Sur or Monterey, is to use the softwareupdate command in Terminal. Sometimes that may not work, with macOS complaining that it isn’t capable of installing such an old version of macOS/OS X. Look in the main Applications folder for the installer app, whose name should start with Install, and make a copy of that. Once that download completes, the installer app will open and probably inform you that it’s too old to install on that Mac. That will then invite you to confirm that you do want to download the old version.

Simply click on the appropriate link, and that installer page will open in the App Store, where clicking on the Get button should start the download through the Software Update pane. Unfortunately installers aren’t always easy to come by, so in this article I explain the options offered by Apple for obtaining an official and properly signed installer for those versions, as well as how to download old versions of Xcode.Īpple’s support page lists all those installers currently available through the App Store and official downloads going back as far as OS X Yosemite. It might be for an old Mac, or a new Virtual Machine, for example. There are plenty of good reasons for wanting to install an old version of macOS or even OS X.

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