Back in 2014, Apple announced that all iOS 8 apps must support 64-bit binaries.. Since then, the firm has slowly been phasing out support for 32-bit, with iOS 10 beta warning users of potentially decreased system performance when apps supporting the configuration were opened.
At WWDC 2017 earlier this month, Apple finally dropped the hammer on 32-bit devices as well as apps, saying that iOS 11 will not support 32-bit configurations. The move essentially makes the operating system exclusive to 64-bit devices. Now, the company has once again posted reminders about this change in order to expedite the transition.
In two separate blog posts, Apple has reminded developers that apps submitted to the App Store and the Mac App Store should support 64-bit. The company notes that:
64-bit Requirement for Mac Apps
At WWDC 2017, we announced new apps submitted to the Mac App Store must support 64-bit starting January 2018, and Mac app updates and existing apps must support 64-bit starting June 2018. If you distribute your apps outside the Mac App Store, we highly recommend distributing 64-bit binaries to make sure your users can continue to run your apps on future versions of macOS. macOS High Sierra will be the last macOS release to support 32-bit apps without compromise.
64-bit Apps on iOS 11
As a reminder, new iOS apps and updates submitted to the App Store must support 64-bit. Support for 32-bit apps is not available in iOS 11 and all 32-bit apps previously installed on a user’s device will not launch. If you haven’t updated your app on the App Store to support 64-bit, we recommend submitting an update so your users can continue to run your apps on iOS 11, which will be in the hands of hundreds of millions of customers this fall.
It is important to note that since 64-bit support for apps has been compulsory since June 2015, this move primarily only affects apps that have not been updated since then.