Check for 32-Bit Apps

When Mojave was released in 2018, users began to notice that upon launching certain apps, the following alert would occasionally appear: “‘App name’ is not optimized for your Mac and needs to be updated.” What that meant is that the app in question was a 32-bit app, and although it could still work under Mojave, Apple was warning you (and the app’s developer) that it won’t work under Catalina, which requires 64-bit apps.

As a user, you don’t need to know or care about the technical details differentiating 32-bit apps from 64-bit apps. What is relevant, however, is that converting a 32-bit app into a 64-bit app can be a big undertaking for a developer. For some apps—especially those that are older, free, or open-source—that effort might simply not be worth it to the developer. So there’s an excellent chance that one or more apps you use regularly won’t work under Catalina, and some of them may never work on any future version of macOS.

Thus, before you upgrade to Catalina, you should find out which of your apps are still 32-bit apps and then, depending on what you learn, decide on appropriate steps.

Find Your 32-Bit Apps

There are several techniques you can use to identify which of your apps are 32-bit and therefore need to be upgraded or replaced. One way is to open System Information (in /Applications/Utilities), select Applications in the sidebar (under Software), wait a few moments while the app examines your disk, and then look in the “64-Bit (Intel)” column of the table. Apps with “No” in that column won’t run under Catalina.

But there’s a better way: download the free Go64 app by St. Clair Software (developers of Default Folder X and other highly regarded Mac apps). Open the app and click OK. After a few seconds, it lists all your 32-bit apps (including those, marked with an alert icon, which contain one or more 32-bit components), along with helpful information like the date you last used each one and a link to each developer (Figure 4). You can also manually fill in upgrade costs, to help you estimate how expensive it will be to use Catalina.

Update Other Apps

The Catalina installer looks for, and disables, certain types of incompatible software—but there’s no guarantee it will find everything (and I should note that it does not remove 32-bit apps—they’ll still be present, they just won’t work). Given the choice, you’re usually better off upgrading third-party software before you install a new version of your operating system. In cases where low-level incompatibilities exist, especially with things like drivers, preference panes, and kernel extensions, you can save yourself grief by preventing, rather than fixing, the problem.

Apple built an update mechanism into the App Store, so any apps you downloaded from the App Store can also be updated there—and App Store updates are free. To check for and apply App Store updates:

1. Open the App Store app by choosing Apple  > App Store. (In Mavericks or earlier, choose Apple  > Software Update.)

2. Click Updates in the toolbar to display a list of available updates.

3. To update a single app, click the Update button next to it. Or, to update all the listed apps at once, click Update All.

4. If prompted to do so, enter your Apple ID and password, and click Sign In.

The App Store downloads and installs the updates automatically.

Software that doesn’t come from the App Store must use a separate update mechanism. Happily, most modern apps contain some sort of update feature. Unhappily, they don’t all work the same way. Some check for updates every time they’re launched, or on a fixed schedule, while others check only on demand; of those that do check automatically, not all have this feature turned on initially. Some programs can download and install new versions of themselves automatically, while others download a disk image and expect you to open it and run the installer yourself; still others do nothing but open a webpage with links to updates you can download manually.

For now, do the following. In each non–App Store program that you use frequently, look for a Check for Updates command (the wording may vary). Such commands (Figure 5) usually appear in the application menu, the Help menu, or the Preferences window.

While you’re at it, check each app’s Preferences dialog for a checkbox that enables scheduled updates, and if you can choose how often to check, choose the most frequent option. That way, even if an update isn’t available now, you’ll be informed as soon as the next update becomes available and you launch the app.

If you’ve installed any Unix software on the command line, that will need to be updated too—and, in some cases, relocated. Unfortunately, much software of this sort is compiled specially for each version of macOS, so those updates—unlike most software updates—are better performed after you upgrade to Catalina. See Final Software Advice, later, for details.

Use Disk Utility in El Capitan or Later

If your Mac is running El Capitan or later, follow these steps:

1. Launch Disk Utility (in /Applications/Utilities).

2. In the list on the left, select your startup volume (if it isn’t already selected; Figure 6).

   

3. Click First Aid on the toolbar, and then click Run. Disk Utility checks your disk and repairs it if necessary. (Depending on your version of macOS, you may also see an alert notifying you that your Mac will be frozen while the First Aid process runs.)

4. When First Aid is finished, click Done and quit Disk Utility.

Use Disk Utility in Yosemite or Earlier

In Yosemite or earlier, Disk Utility can’t repair the volume you booted from, so you’ll have to use a different procedure that requires a secondary startup volume. Follow these steps:

1. Start up your Mac from media other than your regular startup volume that also contains Disk Utility. This could be, for example:

   • A bootable duplicate of your startup disk stored on an external hard drive or a second internal drive

   • A Mac OS X installation DVD or CD

   • A USB Software Reinstall Drive

   • The hidden Recovery HD volume on a Mac running 10.7 Lion or later, which enables OS X Recovery (choose Apple  > Restart and immediately press and hold ⌘-R to start in OS X Recovery)

2. Run Disk Utility:

   • If you’re running from a bootable duplicate, you can find Disk Utility in /Applications/Utilities.

   • If you’re running from a Mac OS X installation disc or USB Software Reinstall Drive, click through the language selection screen and then choose Utilities > Disk Utility.

   • If you’re using OS X Recovery, click through the language selection screen if it appears, select Disk Utility, and click Continue.

3. At the left, select your regular startup volume (the one to repair, not the one from which you’re currently booted).

4. On the First Aid pane to the right, click Repair Disk.

   Disk Utility looks for common errors and repairs them if possible. Ordinarily, it displays a message saying that repairs were completed or that no repairs were necessary.

5. Quit Disk Utility.

6. Restart your Mac:

   • If you find yourself within the installer, quit the installer too; then, click Startup Disk, select your main disk, and click Restart.

   • Otherwise, choose Apple  > Restart.

If Disk Utility encounters a serious problem that it cannot solve, you may need to use a commercial repair tool such as TechTool Pro 11, which most experts recommend as their top pick—or restore your entire disk from a bootable duplicate or other full backup. Alternatively, you could erase your entire disk (after updating your duplicate one last time) and start over from scratch with Catalina, transferring all your apps and personal files from your duplicate after the installation, as I describe in Plan B: Clean Install.