Just recently Apple revealed that support for 32-bit apps on macOS will soon be phased out of the operating system. Users on the latest version of the OS are seeing a warning dialog when opening 32-bit apps. It’s very similar to the process used with iOS when that operating system dropped 32-bit app support. You probably have at least some 32-bit apps on your computer (Apple, embarrassingly, has several of their own). How do you check for 32-bit apps on your Mac?
What’s Happening to 32-Bit Apps?
On April 12th Macs running High Sierra (10.13.4) started displaying alert windows when launching 32-bit applications. This warning advises users that 32-bit applications need to be updated by the developer to “improve compatibility.” If you click the “OK” box, the application launches normally. You can also click “Learn More …” to visit an Apple Knowledge-base article about why this is happening.
The language could be clearer, but this is the first sign that Apple is phasing out support for 32-bit apps on macOS. In a future unspecified version of macOS, 32-bit apps will no longer launch. To keep their apps working, developers must update their applications for 64-bit architecture.
The dialog box doesn’t say when support for 32-bit apps will be phased out entirely, but it’s probably not any time soon. Apple gave iOS developers nearly three years to update their 32-bit apps to 64-bit before shutting down 32-bit support on iOS 11.
If this warning has inspired some anxiety, fear not: 32-bit apps will not harm your Mac, nor will your computer run slower for having them. These apps also won’t run more slowly than they did before.
Why Is This Happening?
This is happening because Apple is phasing out support for 32-bit applications in macOS. 32-bit apps use 32-bit numbers, which use thirty-two ones and zeros to represent numbers in the program. This smaller number space limits the app itself and the app’s compatibility. Without 64-bit support, apps can’t access as much memory or use modern Mac technologies like metal graphics processing. Outside of compatibility issues, there are few good reasons for modern apps to run in the outdated 32-bit mode. The move towards 64-bit has been a long time coming and should not surprise developers.
Apple can also realize an additional benefit. When iOS dropped 32-bit support, Apple took the opportunity to purge old and outdated apps from the App Store. Apple should take the same approach with the Mac App Store. If developers can’t get around to updating their apps for 64-bit support, it’s likely the app has been entirely abandoned. Removing abandoned apps from the App Store is always a good idea. It’s like a forest fire: clearing out dead material to make room for new life. Hopefully, Apple sees this purge as the first step in improving the Mac App Store’s dismal state.
Check for 32-Bit Apps on Your Mac
If you’d like to see how many 32-bit apps are on your Mac, you can check that through System Report.
1. Click the Apple menu in the menu bar and choose “About this Mac …”
2. At the bottom of the window click the “System Report” button.
3. Find the “Software” heading in the sidebar on the left. If the menu under “Software” is collapsed, click the disclosure triangle to expand the menu.
4. Select “Applications” under the “Software” menu.
5. Look for the column titled “64-bit (Intel)” which appears all the way at the right. You’ll probably need to scroll or expand the window to view the column.
A “Yes” in this field means the app is updated for 64-bit operation. A “No” means the developer will need to update the app to work with future versions of macOS. Click the top of this column to sort by this column’s values. Don’t be surprised to find some older Apple apps marked with No.
6. Clicking the title of the column will sort all the applications marked “No” to the top of the column. Read across to the application name in the left-most column to identify the applications that need developer attention.
Conclusion: What Can I Do?
If you rely on or like an app that’s still in 32-bit mode, contact the developer to make sure they know you want the app updated. Absent developers might not realize their app has invested users. If you voice your request, you could encourage the developer to update an app they would otherwise let die. If you are not receiving any response from the developers, or they have no intention of updating the apps, then you will want to find alternative apps for your Mac.