32-Bit Apps 'Not Optimized for Your Mac' to Stop Working on macOS Catalina

When macOS Mojave was announced, Apple warned that it would be the last version of macOS that would support older 32-bit apps. Apple has been phasing out 32-bit apps for the last 10 years and is now ready to take the final step, even if Mac users may not be ready to lose access to older apps.

In September, when macOS Catalina comes out, 32-bit app support will not be available, which means many of your older apps could potentially stop working if they're not updated to 64-bit.

32-bit vs. 64-bit

32-bit apps date back to a time when there were 32-bit processors and 32-bit operating systems, but are now outdated. Apple has long since transitioned to 64-bit processors and macOS has been 64-bit since the launch of Snow Leopard in 2009.

Compared to 32-bit apps, 64-bit apps can take advantage of more memory and offer faster system performance. Apple technologies like Metal only work with 64-bit apps, and for Apple to ensure that Mac apps include all of the latest advancements and optimizations, support for 32-bit needs to end. In the simplest terms, 32-bit apps are inefficient.

32-bit apps can run on a 64-bit system as they've been doing for years, but Apple wants to get rid of outdated apps to make sure everything that runs on the Mac is properly optimized and isn't an unnecessary drain on system resources.

Current Warnings

Apple started warning Mac users about plans to end support for 32-bit apps back with macOS High Sierra. In High Sierra, users started getting warnings about a 32-bit app's future incompatibility with macOS.

A similar message is available in macOS Mojave, and if you open up a 32-bit app while running Mojave, you're going to see an alert letting you know a specific app won't work with future versions of macOS unless it's updated.

Alerts re-appear every 30 days when launching an app, with Apple aiming to make sure customers will not be caught unaware when a 32-bit app stops working in the future.

If you're a developer and you update to the beta of macOS Catalina, as soon as you update you'll be shown a list of 32-bit apps that no longer work on your system.

Checking If an App is 32-Bit or 64-Bit

To determine whether an app is 64-bit or 32-bit and to see if there are 32-bit apps installed on your machine, follow these steps:

  1. Click the Apple symbol () in the menu bar on your Mac's desktop.

  2. Click on About This Mac.

  3. Choose "System Report" at the bottom of the window.

  4. Scroll down to the Software list on the sidebar.

  5. Select "Applications."

  6. Scroll all the way to the right to see the 64-bit list.

Anything in this list that has a "Yes" next to it is 64-bit and does not need to be updated. Anything that says "No" will need to be updated.

How to Prepare

The first step is to make sure there aren't already available updates for apps that you have on your system, which you can generally do by updating through the Mac App Store for Mac App Store apps.

Apps outside of the Mac App Store use other update methods that can vary by app, but for many, you can click on the app's name in the menu bar and choose the "Check for Updates" option. Some other apps have more hidden update methods, so if you do have a 32-bit app, make sure to Google how to update it to be sure there's not already new software available.

After ensuring you've updated everything you're able to update, you can contact developers and ask them to update their apps, but if that doesn't pan out, the only other solution is to start the search for an alternative app now so you're ready when the next-generation version of macOS launches.

Outdated Apple Apps and Files

There are many apps that are going to stop working. One major example is Aperture, and Apple recently warned current Aperture users that Aperture is not going to run on future versions of macOS.

If you're an Aperture user, now is the time to transition to alternate photo editing and management software, such as Adobe's Lightroom.

Affected Media Formats

Certain media files that use older formats and codecs are also not going to be compatible with macOS after macOS Mojave due to the 64-bit transition, and you will need to convert some iMovie and Final Cut Pro X libraries. Incompatible media files were created using codecs that rely on QuickTime 7, and while macOS Mojave has QuickTime 7 frameworks, future versions of macOS will not.

Apple has a full list of media formats that are going to be affected by the transition available in a support document.

Continuing to Use 32-Bit Apps

In macOS Mojave and earlier versions of macOS like High Sierra, you can continue to use your 32-bit apps. If you have a 32-bit app that you absolutely depend on, you're going to want to think twice before upgrading to macOS Catalina when it's released.

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