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Will Mojave (macOS 10.14) Support 32-bit Apps?

September 11, 2018 GMT

There has been some confusion about the status of 32-bit apps in macOS 10.14 Mojave, which will be available soon (for free).

I’ve got advice for you on handling the upcoming transition from 32-to-64-bit apps… But first, if you don’t already know what a “32-bit app” is, or why it might matter, here’s a brief excerpt from a relevant Apple tech note:

All modern Macs include powerful 64-bit processors, and macOS runs advanced 64-bit apps, which can access dramatically more memory and enable faster system performance. The technologies that define today’s Mac experience—such as Metal graphics acceleration—work only with 64-bit apps. To ensure that the apps you purchase are as advanced as the Mac you run them on, all future Mac software will eventually be required to be 64-bit.


Apple began the transition to 64-bit hardware and software technology for Mac over a decade ago, and is working with developers to transition their apps to 64-bit. At our Worldwide Developers Conference in 2017, Apple informed developers that macOS High Sierra would be the last version of macOS to run 32-bit apps without compromise.

While developers optimize their apps for 64-bit compatibility, Apple is notifying customers when they are using an app based on 32-bit technology. This is done via a one-time alert that appears when you launch a 32-bit app.

You may have seen that alert in High Sierra (I saw it regularly) and wondered what will happen when you upgrade to macOS Mojave.

Here’s good news: I’ve been using beta releases of Mojave all summer as I wrote macOS Mojave For Dummies. And, in my (albeit limited) testing, most if not all of the 32-bit apps that worked in High Sierra (10.13) continued to work in macOS Mojave (10.14).

The bad news is that will cease working next year when macOS 10.15 ships.

So, to do is identify your 32-bit apps, choose About This Mac in the Apple menu and then click the System Report button. In System Report’s Software section, click Applications and then click on the column name—64-bit (Intel)—to sort the applications. If it says, “Yes,” the app is 64-bit; if it says, “No,” the app is 32-bit.

Now that you have identified your 32-bit apps — I have 140 of ’em but I’m known to be an App hoarder—what next?

Here’s my advice: If an app runs OK under High Sierra and Mojave, you don’t have to do much, at least not immediately. One thing I recommend is that you don’t delete it yet. Its developer could still update it to 64-bits before the next version of macOS ships.

In the meantime, you might want to start thinking about a replacement for it in the event it’s not updated in time (i.e. before you upgrade to macOS 10.15 next year).