What is Rosetta 2 on Mac, and do you still need it?

What Rosetta 2 does on a Mac

Rosetta is Apple's compatibility layer for the transition from Intel processors to Apple silicon. It works in the background when supported Intel software runs. There is no normal Rosetta window to open, and installing it doesn't change the computer's processor.

That distinction answers two common confusions. An Apple silicon Mac remains Apple silicon while running an Intel app. And an Intel Mac doesn't need Rosetta 2 to run its own Intel software; it cannot use Rosetta as a way to run Apple-silicon-only code.

Prefer the developer's Apple silicon or Universal version when one is available. Translation is a compatibility route, not a reason to choose an old Intel installer over the supported native one.

Apple's current Rosetta support plan

Apple's guidance updated 21 September 2026 states that Rosetta is available on Apple silicon with macOS 27 or earlier. Starting with macOS 28, it will be available only for certain older, unmaintained games that rely on Intel-based frameworks.

That is a version-based boundary. Don't substitute an assumed calendar year or interpret the games exception as a promise that every Intel application will keep running. A work app, plug-in or updater should have an Apple silicon plan of its own.

For the versions covered by this guide—macOS 15 Sequoia, macOS 26 Tahoe and macOS 27 Golden Gate—Rosetta remains the supported compatibility mechanism Apple documents. If you rely on it, use the time before a future upgrade to identify the dependency rather than discovering it after upgrading.

Find out which apps still need translation

In Finder on all three versions, locate the app, usually in Finder › Applications. Select it and choose File › Get Info, or press Command-I. Apple's current instructions identify these values after Kind:

• Application (Intel): built for Intel. Check for a supported Apple silicon update.
• Application (Universal): contains support for both Apple silicon and Intel.
• Application (Apple silicon): built for Apple silicon.

On macOS 27, Apple also provides System Settings › General › About › Intel-based Apps › Details in the macOS section. This list includes recently used apps and apps found in common locations. It is an inventory aid, not a guarantee that every nested or rarely used component has been found.

macOS 15 and 26 don't have that documented macOS 27 list. Use Finder's Get Info route instead. When investigating a running app, open Activity Monitor and enable View › Columns › Kind in its CPU view if needed. Apple identifies a native running process; Intel identifies Intel code running through translation on Apple silicon. A Universal app can run either way, depending on its launch setting. Don't confuse one helper's architecture with the whole Mac.

Install Rosetta when a trusted app needs it

First confirm that the app came from its genuine developer or the App Store. An installation prompt is not evidence that an unknown download is safe. Check whether the developer already offers a native build before adding a compatibility dependency.

1. Connect the Mac to the internet.
2. Open the Intel app you intend to use. If it opens, Apple says Rosetta is already installed and working in the background.
3. If macOS asks to install Rosetta, follow that system prompt. Apple documents clicking Install and authorizing with the Mac's user name and password.
4. Open the app again if needed. Check the actual task and its add-ons, not only whether the application window appears.

No separate Rosetta download from a third-party site is needed. Apple also documents a Terminal installation method, but the system prompt is enough for this workflow. We have not installed or removed software to produce this guide.

On a managed work or school Mac, ask IT if installation is blocked. Don't remove management or weaken security settings to make an old app launch.

What “Open using Rosetta” means

A Universal app may offer Open using Rosetta in its Finder Info window. Apple says the developer chooses whether to include that option. It makes the Universal app open as Intel software so it can use Intel-only plug-ins, extensions or other add-ons.

If you use that setting, record why. An audio application with an old plug-in is a different case from an ordinary app whose native version works without add-ons. Once the required add-on is available for Apple silicon, Apple's instruction is to clear the setting.

Don't switch the option blindly to chase speed. The useful test is whether the full supported workflow works natively with compatible add-ons. Save projects and confirm backups before changing a professional setup that depends on particular plug-in versions.

Replace the dependency, including the small components

Start with the App Store, the app's built-in updater or the developer's genuine website. Our app-update guide covers those routes. Read the release notes for native support and any project or licence migration requirements.

Apple specifically warns that an app can include components needing separate updates. A native main app with an Intel-only extension, updater or third-party plug-in may still show a compatibility warning. List the actual components you need and ask their respective developers about supported versions.

If no native version exists, ask whether one is planned and whether your data can be exported to a supported alternative. Keep a copy of the original files and any export. A backup preserves the files; it doesn't create a future-compatible version of the app that reads them.

A useful inventory has the app name, current version, important add-ons and the vendor's supported macOS versions. Recheck it before a major macOS upgrade. Don't treat an installer saved years ago as a support guarantee.

Performance and removal: avoid generic claims

Apple recommends native software for optimal performance and future compatibility. This guide has no controlled before-and-after measurements, so it doesn't attach an invented CPU penalty, power saving or battery-hour difference to Rosetta.

If you are troubleshooting slowness, test the same supported task with a current native app rather than crediting every change to translation. Different app versions can change many things besides processor support. Use the slow-Mac diagnosis to check the workload and memory pressure.

There is no need to force-remove Rosetta just because every app you recognize is now native. Removing protected system components is not part of Apple's update recommendation. Focus on replacing the software dependency and keeping macOS current.

Where Tend fits

Tend's free per-app CPU, memory and estimated watts can provide context while comparing a workflow before and after an app update. It doesn't prove Rosetta caused a difference or convert an app to native code. Free energy history covers 24 hours; Pro adds 7- and 30-day totals.

Questions

Related guides

Sources

Sources checked 23 October 2026. These are documented steps and specifications; no repair, installation or performance test was run for this guide.

• Apple, Using Intel-based apps on a Mac with Apple silicon — updated 21 September 2026
• Apple, Mac computers with Apple silicon
• Apple, View process information and choose Activity Monitor columns
• Apple Developer, Port your Mac app to Apple silicon — Activity Monitor Kind column

Spotted something out of date? Tell us and we'll fix it.