# What is Rosetta on a Mac?

> Rosetta is Apple's translation layer that lets Intel apps run on Apple silicon Macs. Learn when macOS asks to install it and why a universal app avoids it.

Canonical: https://www.notchstar.com/glossary/rosetta/
Last updated: 2026-11-04

Published 2026-11-04.

Rosetta is Apple's translation layer for the Mac. It lets apps written for Intel processors run on Macs with Apple silicon. Apple says it works in the background to translate those apps automatically, so you never open it yourself.

## Why it matters

You may meet it as a prompt. When you open an Intel based app on an Apple silicon Mac and Rosetta is not installed, macOS asks whether to install it, and you click Install and enter your password. Apple also documents a Terminal command, `softwareupdate --install-rosetta`, for installing it by hand.

Translation costs some speed, and an app that uses it is not running as the Apple silicon version would. Apple's page says Rosetta is available on Apple silicon Macs through macOS 27, and from macOS 28 it will support only certain older games that depend on Intel frameworks. Check Apple's page for the current wording.

## NotchStar and Rosetta

NotchStar is a [universal binary](https://www.notchstar.com/glossary/universal-binary/). On an [Apple silicon](https://www.notchstar.com/glossary/apple-silicon/) Mac it runs natively and does not need Rosetta. On an Intel Mac there is nothing to translate.

## Related

Read [is NotchStar safe](https://www.notchstar.com/guides/is-notchstar-safe/) for how the download is built and signed, and the [System tool](https://www.notchstar.com/features/system-stats/) to see live CPU load.

## Keep reading.

- [What is Apple silicon?](https://www.notchstar.com/glossary/apple-silicon/): Apple silicon is the family of Apple designed chips that replaced Intel processors in Macs. Learn how to tell which chip your Mac has and why apps care.
- [What is a universal binary on Mac?](https://www.notchstar.com/glossary/universal-binary/): A universal binary is one Mac app file that contains code for both Apple silicon and Intel chips, so it runs natively on either. Learn how to check one.
- [Is NotchStar safe? Signing, permissions and what it sends](https://www.notchstar.com/guides/is-notchstar-safe/): NotchStar is signed and notarized by Apple, needs no account and sends nothing unless you opt in. See every permission it asks for and how to check it yourself.
- [CPU, memory, disk, battery and network](https://www.notchstar.com/features/system-stats/): Live CPU, memory, disk, battery and network speed gauges in your Mac notch. Sampling only runs while the tab is open, so it stays light.

## More in Mac basics.

- [What is the MacBook notch?](https://www.notchstar.com/glossary/notch/): The notch is the cutout at the top of some MacBook screens that holds the camera. Here is what it is, which Macs have it and what it does to the menu bar.
- [What is the Mac menu bar?](https://www.notchstar.com/glossary/menu-bar/): The menu bar is the strip along the top of a Mac screen with the Apple menu, app menus and status icons. Learn how it works and how the notch changes it.
- [What is the safe area on a Mac screen?](https://www.notchstar.com/glossary/safe-area/): The safe area is the part of a screen where content is not covered by hardware such as the notch. Developers read it from NSScreen safeAreaInsets in AppKit.
- [What is AirDrop?](https://www.notchstar.com/glossary/airdrop/): AirDrop sends files wirelessly between nearby Apple devices. Learn what it needs, how to use it on a Mac and how a notch file shelf can start a send.
- [What is Universal Clipboard?](https://www.notchstar.com/glossary/universal-clipboard/): Universal Clipboard lets you copy on one Apple device and paste on another nearby one. Learn what it needs and how it differs from clipboard history.
- [What is Apple silicon?](https://www.notchstar.com/glossary/apple-silicon/): Apple silicon is the family of Apple designed chips that replaced Intel processors in Macs. Learn how to tell which chip your Mac has and why apps care.