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How to tell if an app is running under Rosetta on your Mac

· 4 min read

To tell whether an app runs under Rosetta, check its Kind. Select the app in Finder and press Command-I: if Kind says “Application (Intel)”, the app is built only for Intel Macs and your Apple silicon Mac runs it through Rosetta. “Application (Universal)” means it contains both versions and runs natively, as does an app built only for Apple chips. The same answer is available for every app at once in System Information, and for apps that are running right now in Foreman.

This only applies to Macs with an Apple chip. An Intel Mac runs Intel apps directly and has no translation step.

What Rosetta is

When Apple moved Macs from Intel processors to its own chips, apps built for Intel could not run on the new processors as they were. Rosetta is the translator that makes them work anyway. The first time you open an Intel-only app on an Apple silicon Mac, macOS may offer to install it, and after that the app simply opens.

For most people it is invisible. The app works, so there is no reason to think about it. The reasons to check are the ones below.

Method 1: Get Info on one app

  1. In Finder, open the Applications folder and select the app.
  2. Press Command-I, or choose File > Get Info.
  3. Look at Kind near the top.

What it tells you:

  • Application (Intel): built only for Intel. It runs through Rosetta.
  • Application (Universal): contains both versions. On an Apple silicon Mac it runs natively.
  • A label naming Apple silicon: built only for Apple chips. Native.

One catch: a Universal app shows an “Open using Rosetta” checkbox in the same window. If it is ticked, the app runs through Rosetta even though a native version is inside. Untick it unless the app’s maker told you to use it, for example for an old plug-in.

This is the quickest check for a single app and needs nothing installed.

Method 2: System Information for all apps at once

  1. Hold Option and open the Apple menu, then choose System Information.
  2. In the sidebar, under Software, choose Applications.
  3. Wait for the list to fill. Look at the Kind column: it reads Intel, Apple Silicon or Universal for Mac apps (iPhone and iPad apps show iOS).

Click the Kind header to sort. Every Intel-only app is now grouped together. This is the best way to audit a whole Mac, and it includes apps you are not currently running.

Method 3: Terminal

For a single app, ask what kind of program file is inside it:

file /Applications/Name.app/Contents/MacOS/Name

Replace Name with the app’s name. If the output mentions arm64 (or arm64e), the app has a native version; a Universal app lists both x86_64 and arm64. If it mentions only x86_64, it is Intel-only. The program file inside the bundle does not always carry the same name as the app, so look in the app’s Contents/MacOS folder if the command cannot find it. The file command is part of every Mac, only reads, and changes nothing.

Method 4: see which running processes are Intel

The methods above describe files. If you want to see which programs are running right now under Rosetta, including helpers an app starts that you never see in the Applications folder, Foreman has this on its All Processes page. One of its columns is Architecture, and it shows Intel apps running through Rosetta, so you can read down it for the Intel ones.

That is useful because an app can be native while a helper tool it bundles is Intel, and the helper’s cost lands on your Mac without appearing in the app’s Kind. It is also handy for finding which process is the Intel one when the Mac feels slow, because you can check the Architecture and the processor columns side by side.

Does it matter

Sometimes, and rarely in a way you will feel. Translation adds work, so an Intel-only app generally uses more of the processor, and so more battery, than a native version doing the same job. For an app you use for a minute at a time, nobody notices. For an app that runs all day, or does heavy work such as editing or building, the difference can show.

I will not give a number, because it varies enormously with the app and the task. The honest advice is to look at the apps you leave open for hours and the apps that do your heaviest work. Those are the ones where a native build pays back.

Two other reasons to care:

  • Rosetta cannot translate kernel extensions, the kind of driver that loads into the core of macOS, so an Intel-only driver of that kind will not work on an Apple silicon Mac at all.
  • An Intel-only app is often one its maker has stopped updating, and Apple has said Rosetta will not stay a general-purpose part of macOS forever. Anything you depend on is worth moving to a native version while you have the choice.

What to do about an Intel-only app

  1. Check for an update. Many apps went universal in a later release. Use the app’s own Check for Updates item first, or the App Store if that is where you got it.
  2. Look at the maker’s download page. Some offer separate Apple silicon and Intel downloads, and people who installed the Intel one by mistake stay on it. Download the Apple silicon build and replace the old one.
  3. Look for a native alternative. If the maker has stopped updating, a search for a similar app that lists Apple silicon support is reasonable.
  4. Keep it if it works. An Intel-only app that does its job and is not heavy needs no action.

If a heavy Intel-only app is the one slowing your Mac, How to speed up an old Mac without buying anything lists other free steps, and How to find which app is draining your MacBook battery helps you decide whether it is worth replacing.

Summary

Press Command-I on an app and read Kind. Intel means Rosetta, Apple silicon or Universal means native. For the whole Mac, sort the Applications list in System Information by Kind. To catch helpers and see what is running now, Foreman’s All Processes page has an Architecture column. Update or replace what matters, and leave the rest alone.