While your Mac model may support macOS Sonoma, not all features may be available. Certain features require specific Mac models with Apple Silicon.

Fortunately, there’s a way to review your system upgrade history, though you may have never needed to dig it up before: Hold down Option while choosing the menu and select System Information.

Finally, though it may seem obvious, make sure that you are using the proper standalone updater for your system -- either the standard Mac OS X 10.4.2 client or Mac OS X 10.4.2 Server.

Here are the Macs that will support macOS 13. Different from macOS Monterey, which supported a ton of Macs, Apple is closing the gap between the Intel Macs and its own.

MacOS Big Sur is available for download now, so long as you have one of these supported Apple devices.

There are two versions, one for System 7 and the other for Mac OS 8, which laid the foundations for what would become Mac OS X, later renamed to OS X and then to macOS.