Rosetta 2 is necessary if you want to be able to run older non-native Intel x86 apps on new Apple Silicon Macs, like the M1 MacBook Pro, MacBook Air, or Mac mini. Curiously, Rosetta 2 is not installed by default on these Macs however, so if you wish to run these apps you’ll need to install Rosetta 2 onto the Apple Silicon Mac yourself.
There are two ways to install Rosetta 2 onto an Apple Silicon Mac; using the Terminal, or by attempting to open a non-native x86 app which prompts an installer. You can use whichever method you’d like, as both will have the same end result of Rosetta 2 being installed onto the Mac.
Remember, this is only for Apple Silicon ARM Macs, and this is not necessary on any Intel Mac (nor would Rosetta 2 install on Intel Macs anyway). Also, this capability is only available in macOS Big Sur or later.
How to Install Rosetta 2 via App Launch
If you have any x86 Intel apps available on the Apple Silicon Mac, simply launching the app will prompt the user to install Rosetta. Clicking “Install” will then install the Rosetta 2 software onto the Mac.
How to Install Rosetta 2 via Command Line on Apple Silicon Mac
Another way to install Rosetta 2 on the Mac is by using the familiar softwareupdate command line tool.
This will launch the rosetta installer and you’ll have to agree to a license agreement, which I’m sure you’ll read completely and thoroughly as we all do every time we install anything on every device.
You can also skip the license agreement by providing an additional flag:
/usr/sbin/softwareupdate --install-rosetta --agree-to-license
For some quick background, new Apple Silicon Macs run on different architecture, whereas Macs have been running Intel chips for quite some time. Rosetta 2 translates Intel x86 code to ARM so that it can run on the new Apple Silicon hardware. You can read more about the Rosetta 2 translation environment at the Apple developer site gif interested.
And if the name Rosetta sounds familiar to you, it’s likely because Apple used the same name for a similar translation process when Apple moved from PowerPC (PPC) to Intel architecture, support for which was later dropped in Lion. Or maybe you’re familiar with the Rosetta Stone language learning software, or even the original Rosetta Stone Egyptian tablet… but anyway, for our purposes here it allows new Apple Silicon Macs to run older apps that are not yet native.
Over time, more and more Mac apps will run natively on Apple Silicon, and Rosetta 2 will eventually become unneeded, in much the same way that Rosetta for PowerPC eventually became deprecated. But that’s still years away, as Apple is just at the beginning of the process of bringing Apple Silicon to the Mac hardware lineup.
Rosetta is a translation process that allows users to run apps that contain x86_64 instructions on Apple silicon.