What is Rosetta 2 and how does it work on Macs with M1, M2, and M3 chips?

If you have a Mac, you may have heard of Rosette 2This is the component that allows many long-standing programs to continue running with an Apple chip. Rosetta 2 is Apple's translation layer for running Intel apps on Apple SiliconAnd although it acts invisibly, it is worth knowing how it works, how it is installed, its limits and what will happen to it in the future.

In the following lines you will find a complete guide, with real tricks and practical cases. You will learn how to identify if an app needs Rosetta, how to install it automatically or from Terminal, and understand its impact on performance and resource consumption., plus an extra section in case you need to recover data after a failed installation.

What is Rosetta 2 and what is it used for?

Rosetta 2 is a dynamic binary translator created by Apple for macOS on computers with Apple Silicon processors. Its mission is to convert, on the fly or in advance, the code of apps compiled for Intel x86_64 to ARM64 instructions. Apple chips understand, so these applications can be used without the developer touching a single line of code.

It's not an app you open or configure; in fact, you won't see an icon in the Dock or a preferences panel. Rosetta 2 activates automatically when you open an application designed specifically for Intel.It translates your code and lets you use it as if nothing happened. In most cases, the behavior is transparent to the user.

A little history: from the original Rosetta to Rosetta 2

Apple had already used a technology with the same name during the transition from PowerPC to Intel in 2006. That original Rosetta, included in Mac OS X Tiger, translated G3 and G4 instructions (including AltiVec) but not G5Therefore, apps that relied on G5 instruction sets could not run unless developers adapted them.

The old version had significant limitations: many computationally intensive applications (e.g., ray tracers or certain video games) malfunctioned or were simply incompatible. Some professional Apple apps from that era (Final Cut Pro, Motion, Aperture, Logic Pro) required "crossgrading" to universal binaries to run natively on Intel instead of going through Rosetta.

There was also a long list of incompatibilities. The original Rosetta did not support the Classic Environment (Mac OS 9 or earlier apps), kernel extensions, and software that depended on them., screen savers, apps that required very precise exception handling, nor certain Java apps (including some with JNI libraries), among other cases.

The technical reason for many of these restrictions lies in their design. The original Rosetta functioned as a user-space process which could only intercept and translate user code, unlike the old 68k emulator (much more closely coupled at a low level with the nanokernel), which meant less room to intercept certain system operations and, in return, less risk of debugging and security.

How Rosetta 2 works on current macOS

Rosetta 2 modernizes and refines that idea for the transition from Intel to Apple Silicon. It dynamically translates x86_64 binaries to ARM64 and, in many cases, performs forward translation. The first time you open the app, it speeds up subsequent executions. With apps focused on user interaction and moderate loads, performance is usually very good.

Apple still recommends looking for native versions whenever possible and getting to know the characteristics of ARM computers. Although most users don't notice any obvious performance differences, native apps take full advantage of the chip's potential. and they tend to consume fewer resources, which can also translate into less energy expenditure.

Compatibility: how to know if an app needs Rosetta

macOS lets you check it from the Finder in seconds. Select the app icon, go to File > Get Info, and look at the Type or Class field.You will see one of these labels:

• Application (Intel): Requires Rosetta 2 to run on an Apple-chip Mac.
• Application (Universal): includes binaries for Apple Silicon and Intel; does not require Rosetta and uses Apple Silicon by default.

There is also a special box in some universal apps. The “Open with Rosetta” option allows a universal app to load plug-ins or extensions that are not yet adapted to Apple SiliconIf an add-on stops appearing or isn't working, exit the app, enable this option, and try again.

Rosetta 2 Automatic Installation

Rosetta 2 is only available on Mac computers with an Apple chip. You need an internet connection to install it the first time.because macOS downloads components from Apple's servers.

1. Open any app that requires it. If the app starts, Rosetta is already installed and working..
2. If it's not installed, macOS will display a prompt to download it. Click Install and authenticate with your username and password to allow installation.
3. If you choose "Not now", nothing happens; macOS will ask you again when you try to open another app that needs it..

If the notification does not appear when you open the app, it could be for two reasons: Either Rosetta 2 is already installed, or that application doesn't need it. because it is universal or native to Apple Silicon.

Installation from the Terminal (force installation)

In some scenarios (for example, when no Intel app triggers the installation or after a failure), you can install Rosetta 2 from Terminal. Open Terminal and use the software updater command:

softwareupdate --install-rosetta

You'll also see guides that use the full path and accept the license in the same command. It is valid to run the variant with the path and license acceptance:

/usr/sbin/softwareupdate --install-rosetta --agree-to-license

With either one, if there's a connection and the Mac is Apple Silicon, The installation is completed in a few seconds and Rosetta becomes available for all apps that require it..

Zoom, PASCO Capstone and LockDown Browser on Mac with M1/M2

A recurring question is whether apps labeled as Intel 64 work on a Mac with an Apple chip. The general answer is yes, they run using Rosetta 2 as long as they do not depend on kernel extensions or legacy hardware. Not supported on Apple Silicon.

Regarding specific cases: Zoom has a native version for Apple Silicon and also works via Rosetta 2 if you install the Intel variant.It is recommended to download the native edition from their website for best performance.

For PASCO Capstone and LockDown Browser (Cengage OEM), If they are categorized as Intel 64 and do not install incompatible kexts or drivers, they will normally work through Rosetta 2.However, always check the official guide from each provider and the latest versions.

If you have any doubts, perform this check: Open the app, and if macOS prompts you to install Rosetta, complete the process; if the app opens without errors, it's compatible via translation.You can also check the app type as explained earlier in Get Information.

“Open with Rosetta” in universal apps

There is a specific box that you will see in some universal apps. Enabling “Open with Rosetta” causes an app that is already native to run under the translatorAnd it makes sense when you need to use an add-on, extension, or plug-in that isn't yet adapted to Apple Silicon.

If an extension doesn't appear, try this: Close the app, check the box, reopen it, and check if the add-on is now recognized.When that plugin is updated, you'll be able to uncheck the option to restore native performance.

Limits and incompatible cases

Although Rosetta 2 covers the vast majority of user scenarios, not everything is translatable. As in the previous transition, the translator does not run kernel extensions or software that depends on them.nor does it solve the lack of legacy hardware interfaces.

The Rosetta story (original version) listed several exclusions that help to understand the risk profile. The following were not compatible: Classic Environment, Mac OS 9 and earlier apps, certain screen savers, apps with very precise exception handling, and certain Java binaries with JNI.Rosetta 2, although more modern, maintains the principle: anything requiring very low-level components is usually left out.

Differences with other compatibility “layers”

Rosetta 2 is not virtualization nor a general-purpose emulator of the Intel operating system. Translates x86_64 user binaries to ARM64 so they run on macOSHowever, it does not run Windows or replace tools such as virtualization or Wine/CrossOver technologies for apps from other systems.

This means that, for example, Rosetta 2 cannot be used to launch Windows applicationsIf you need Windows software, you will have to use virtualization (when supported by the vendor), a compatibility container, or a Windows machine.

Availability and roadmap

Following a recent WWDC, public documentation was updated outlining maintenance plans for Rosetta 2. Apple indicates that Rosetta 2 will remain a general-purpose tool for two more major macOS releases (up to macOS 27). to make it easier for developers to finish migrating their apps.

Starting with macOS 28, Apple plans to retain a subset of Rosetta 2 features geared towards older, unmaintained game titles. that depend on Intel-specific macros or programming. This nuance points to a gradual withdrawal from general use.

The same documentation reiterates that macOS Tahoe will be the last version compatible with Intel-based MacsThese devices will, however, receive additional security updates for three years. Intel-based computers compatible with Tahoe include the 2019 16-inch MacBook Pro, the 2020 13-inch MacBook Pro (with four Thunderbolt 3 ports), the 2020 27-inch iMac, and the 2019 Mac Pro.

In parallel, Apple has been updating support articles with recent dates (for example, February 12, 2025 in different locations). It's always advisable to consult the official document for your region to confirm steps and availability.since the nuances of the text or the location may vary.

Quick FAQ

• Is it safe to install Rosetta 2 on a Mac with an Apple chip? Yes. It's an official Apple component downloaded from their servers and designed to facilitate the transition. It's not third-party software and doesn't add any visible panels.
• Can Rosetta 2 run Windows applications? No. Rosetta 2 only translates macOS binaries compiled for Intel to ARM. For Windows apps, you need virtualization, Wine/CrossOver compatibility, or other solutions, depending on the case.
• Does Rosetta 2 slow down the Mac or drain the battery faster? It depends on the app. In most commonly used apps, the impact is small. In intensive tasks, it may increase power consumption and temperature compared to the native version. If there's an Apple Silicon version, install it.
• How do I know if an app is using Rosetta right now? In addition to what you saw in Get Information, check the Type column under Applications in System Report. If it says Intel, it will run with Rosetta on Apple Silicon; if it says Universal or Apple Silicon, it's a native application.

In day-to-day operations, Rosetta 2 is that silent helper that keeps many apps alive while developers complete the migration. Simply open your usual programs: if Rosetta is needed, macOS will tell you and install it.When possible, prioritize native versions to get the most out of Apple's chip and minimize any potential impact on power consumption or storage.