During its Platform State of the Union keynote at the Worldwide Developers Conference, Apple told developers that macOS High Sierra will be the “last macOS release to support 32-bit apps without compromises.”
Starting in January of 2018, all new apps submitted to the Mac App Store must be 64-bit, and all apps and app updates submitted must be 64-bit by June 2018. With the next version of macOS after High Sierra, Apple will begin “aggressively” warning users about 32-bit apps before eventually phasing them out all together.
In iOS 11, 32-bit apps cannot be installed or launched. Attempting to open a non-supported 32-bit app gives a message notifying users that the app needs to be updated before it can run on iOS 11.
Prior to phasing out 32-bit apps on iOS 11, Apple gave both end users and developers several warnings, and the company says it will follow the same path for the macOS operating system.
