iOS developers recently received an email from Apple stating that

Starting February 1st, new apps and app updates submitted to the App Store must be built with XCode 4 and iOS 7 SDK

The email included a link about building apps for iOS 7.

One of the item on this page, is about 64-bit compilation.

So the question is, should I deduce that 64-bit is now a REQUIREMENT, or is it still a recommendation?

  • Nope, definitely not a requirement. It is entirely possible to just build for ARMv7, as the instruction set is backwards compatible. Eventually, ARMv7 will be phased out like ARMv6 was, but until all devices are running the ARM64 instruction set, they must allow apps that don't have 64 bit enabled. – Richard J. Ross III Jan 14 '14 at 9:04
  • XCode with the iOS 7 SDK builds both binaries for you and combines them. – Andrew Larsson Jan 16 '14 at 23:10
  • How about the sentence @"and be built with the iOS 8 SDK". New Apps should be set target support from the iOS8? – Nguyen Duc Dec 18 '14 at 0:32

Apple just announced that starting 1. February 2015, apps have to support 64 bit. Source: https://developer.apple.com/news/?id=10202014a. So, it will then be a requirement.

  • What they actually said is that "new iOS apps uploaded to the App Store must include 64-bit support . . ." It's unclear to me whether or not an update to an existing app is a "new app" for this purpose. – William Jockusch Nov 11 '14 at 11:41
  • @william-jockusch: I'm not sure about that either. However, 9to5mac writes that it also applies to updates. (9to5mac.com/2014/10/20/…) – Benedikt Köppel Nov 11 '14 at 12:44
  • 2
    @WilliamJockusch App updates will require 64-bit support on June 1, 2015: macrumors.com/2014/12/17/apple-64-bit-support-reminder – pkamb Dec 18 '14 at 0:18

64-bit is a recommendation. Since not all devices run 64-bit, they must allow 32-bit apps on the App Store. Only when all devices run 64-bit can Apple enforce such a restriction, otherwise all new apps wouldn't work on older devices.

  • While your answer was correct until yesterday, I had to change the accepted answer to the new one showing the latest development. – nute Oct 21 '14 at 12:05

According to an email from Apple today, 64-bit support will soon be required in new iOS apps and app updates.

Feb. 1, 2015: New Apps
June 1, 2015: App Updates

Dear Developer,

As we announced in October, beginning February 1, 2015 new iOS apps submitted to the App Store must include 64-bit support and be built with the iOS 8 SDK. Beginning June 1, 2015 app updates will also need to follow the same requirements. To enable 64-bit in your project, we recommend using the default Xcode build setting of “Standard architectures” to build a single binary with both 32-bit and 64-bit code.

If you have any questions, visit the Apple Developer Forums.

Best regards, Apple Developer Technical Support


iOS apps use universal binary. That means one app can contain both of 32-bit and 64-bit code.

  • If your device supports 64-bit mode, then your app will be run in 64-bit mode which is a lot faster.
  • If your device supports only 32-bit mode, then 32-bit code will be run.
  • 64-bit Apple processors all have 32-bit compatibility mode, so legacy apps (32-bit only) will just work.

Actually in 32-bit mode, there're two different 32-bit architectures, and Apple is dealing with them very smoothly. Most people don't even know there's different 32-bit modes.

If you're a user, you have nothing to care, and everything will just work. If you're a developer, you code will just work unless you are using some unrecommended hacks.


64-bit is slowly becoming a strong recommendation. For example, the in-app bluetooth picker functionality is only supported on 64-bit devices when running a 64-bit binary. So if you want to use the in-app bluetooth picker, you must build for both 32-bit and 64-bit.

Note that this bluetooth picker functionality is not new. It works just fine on 32-bit devices in a 32-bit app. But it will not work on 64-bit devices in a 32-bit app.

I've gotten confirmation from Apple that they do not consider this a bug and it will not be fixed in iOS 8 GM. You must build for both 32-bit and 64-bit if you want this functionality on both 32-bit and 64-bit devices.

See the discussion here: https://stackoverflow.com/questions/20402973/ipad-air-corebluetootherror-cancelling-picker-as-we-couldnt-communicate-wit

  • "picker functionality is only supported on 64-bit devices when running a 64-bit binary" then "But it will not work on 64-bit devices in a 64-bit app". Am I misunderstanding or is this contradictory? – braden Dec 23 '14 at 19:42
  • You read exactly right, I wrote it wrong; sorry about that. I should have said "will not work on 64-bit devices in a 32-bit app." I've updated my post, thanks much for catching that. – aggieNick02 Dec 31 '14 at 16:18
  • I think we can now see why Apple probably wanted to consider this "not a bug". It is because soon it will be irrelevant because there will not be many 32-bit apps on 64-bit devices. – aggieNick02 Dec 31 '14 at 16:20

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