What Rosetta 2 does
Since 2020, new Macs have used Apple’s own processors (Apple silicon: M1 and later) instead of Intel processors. Apps contain machine code for a specific kind of processor, so an app built only for Intel can’t run directly on Apple silicon.
Rosetta 2 bridges that gap. Apple describes it as a translation process that lets a Mac with Apple silicon use apps built for a Mac with an Intel processor. In most cases the translation happens ahead of time, when an app is installed or first opened, so the app then starts like any other. Code that an app creates while it runs is translated as it runs.
There are things Rosetta never handled. Apple’s developer documentation lists, among others, kernel extensions and virtualization software that runs Intel operating systems: these need a version built for Apple silicon.
How to tell which apps use Rosetta
- One app: in Finder, select it and choose File › Get Info. “Kind: Application (Intel)” means it runs through Rosetta. “Application (Universal)” or “Application (Apple silicon)” means it runs natively.
- Apps that are open now: open Activity Monitor and look at the Kind column: “Intel” means Rosetta, “Apple” means native.
- Every app at once: our guide How to find Intel-only apps on your Mac shows four ways, including System Information and a short Terminal command.
Installing Rosetta 2
Rosetta isn’t installed on a new Mac until something needs it. The first time you open an Intel-only app, macOS asks whether you want to install Rosetta; choose Install and enter your administrator password if asked.
Administrators can also install it from Terminal with Apple’s software update tool: softwareupdate --install-rosetta. The tool asks you to accept Apple’s licence first.
If you only use apps built for Apple silicon, you never need Rosetta.
Rosetta and macOS 28
On 1 September 2026 Apple announced that macOS 27 is the final release to support Rosetta, and that Intel-only apps will no longer run on Macs with Apple silicon after it. Apple keeps Rosetta only for some older, unmaintained games that rely on Intel-based frameworks. From macOS 26.4, macOS may also show a notification when you open an app that relies on Rosetta.
What this means in practice, and what keeps working, is explained in macOS 28 and Rosetta: what stops working. Your options for apps that have no native version are compared in How to run Intel apps on Apple silicon after macOS 28.
Rosetta inside a virtual machine
Apple’s virtualization framework can make Rosetta available to Linux virtual machines. A macOS virtual machine is different: it runs a complete copy of macOS, including that version’s own Rosetta. Keep86 is built on this: it runs macOS 27, which still includes Rosetta, in a hidden virtual Mac. Whether a macOS 28 Mac will still allow Rosetta inside a macOS 27 virtual machine has not been confirmed by Apple; we will test it as soon as macOS 28 betas are available and publish the result.
Common questions
What is Rosetta on a Mac? Rosetta 2 is Apple’s translation layer that lets Macs with Apple silicon run apps built for Intel processors.
How do I install Rosetta 2? Open an Intel-only app and choose Install when macOS asks, or run softwareupdate --install-rosetta in Terminal. There is no separate download.
Does Rosetta slow apps down? Translated apps usually run well, but a native version is faster and more reliable. Apple recommends native versions.
When does Rosetta go away? macOS 27 is the last release that supports Rosetta for apps; from macOS 28 it remains only for certain older games.
Sources
- Apple Developer News, “Upcoming changes to Rosetta support for Intel-based macOS apps”, 1 September 2026 — https://developer.apple.com/news/?id=w5ngl9k2
- Apple Support, “Using Intel-based apps on a Mac with Apple silicon” — https://support.apple.com/en-us/102527
- Apple Developer Documentation, “About the Rosetta translation environment” — https://developer.apple.com/documentation/apple-silicon/about-the-rosetta-translation-environment
- Apple Developer Documentation, “Accelerating the performance of Rosetta” (Virtualization framework) — https://developer.apple.com/documentation/virtualization/accelerating-the-performance-of-rosetta