To see if your Mac's processor is 32-bit or 64-bit, go to the Apple menu and choose About This Mac.
Starting with macOS 10.13.4, Mac users will receive a one-time alert when attempting to run a 32-bit app.
Only a day or two ago, similar notifications were seen by watchOS users, and it seems Apple is on a roll calling developers to improve compatibility of apps. And until then, there's a chance that the 32-bit apps will not work as well as their 64-bit counterparts as Apple optimizes its operating system updates for 64-bit processing.
Developers will have to switch from 32-bit to 64-bit if they want their apps to continue functioning when macOS 10.14 arrives. Furthermore, macOS is capable of running advanced 64-bit programs that have access to much more memory compared to 32-bit apps, and can potentially enable faster system performance. "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 continued. The notice will read that the app is "not optimised" for Apple's platform, but it will still run.More news: Brexit: EU to seek environmental non-regression clause
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Below you will find more information about the alert and what the 64-bit transition means for you. Then scroll down to Software and select Applications.
The tech giant this week will begin warning Mac users that 32-bit applications are not desirable. "Using 32-bit software has no adverse effects on your data or your computer". That update will likely come in September or October of this year, and we can probably expect further details at Apple's Worldwide Developers Conference (WWDC) in June. Also, even Apple hasn't moved all its apps to 64-bit.
For now, the iPhone maker is just giving out warnings, and it has given no specific dates when the OS will totally stop supporting the 32-bit apps.
Nevertheless, one thing is sure, that Apple is serious about phasing out the 32-bit apps soon. It first stopped accepting new apps to the App Store that were not 64-bit, and then later stopped launching them. Thereafter, the company made 64-bit mandatory with the iOS 11.
If you're using an old Apple Watch app that hasn't been updated in a while, you might run into some problems when watchOS 5 lands (likely sometime this autumn). First, the Apple desktop OS has been around longer than the iOS.