December 4th 2017
By Mike Flaminio
2018 is the year the Mac App Store goes 64-bit. In a reminder to developers, 9 to 5 Mac notes that starting January 1, all submissions to the App Store must be 64-bit. Apple is also mandating all existing apps be updated by June 2018 if not updated sooner.
The change follows macOS High Sierra, which is the end of the line for 32-bit apps. The next macOS release, presumably next fall, will only function with 64-bit apps. This timeline seems to line up with the typical macOS development cycle that kicks off in late spring with developer and public betas.
Apple made the deadlines earlier this year at its World Wide Developer Conference. The writing has been on the way for years as Apple transitioned to 64-bit, starting with the PowerPC G5 back in 2003. In 2012, 64-bit went mainstream as the with Mac OS X 10.8 Mountain Lion.
As a reminder, 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. The last macOS release to support 32-bit apps without compromise is macOS High Sierra.