Lowest permitted base SDK for App Store submissions

Question

I'd like to know if Apple states the lowest permissible base SDK for submission to the iOS App Store. There was a statement somewhere around 2010 that said you need to use at least SDK 4, but i cannot find this any longer.

Now, before you jump me, I always build against the latest base SDK. The reason i ask this question is because i want facts to counter some customer requests.

Answer 1

Apple seems to have never explicitly required any Base SDK above iOS 3.0 as far, as far I can find, today, either in their app submission guidelines or any official developer email. Thus, there likely is no such link as you require. However there are many indirect hints.

As of 2013-May-01, Apple indirectly requires a Base SDK of 6.0 for submitting iPhone apps by requiring 4" display support and no longer approving any apps where 4" support was added using any Base SDK lower than 6.0 (that latter stated in their enrolled developer forums, login required). This requirement may or may not apply to iPad-only apps, where Apple might still allow submission using a Base SDK of 5.1.

There is a statement (in their enrolled developer forums, login required) from an Apple employee that currently a Base SDK of 7.0 or higher is not required for app submission, but with no date given as to when this may or may not change.

Note that if a developer uses an SDK lower than 7.0 to build an app, they still need to test the app on a iOS 7.x device or risk rejection by Apple if the app fails to run properly on such a device.

The Deployment Target of an app can get set to a much lower OS version. But an iOS Base SDK of 6.0 lacks armv6 support, and thus doesn't allow XCode to build an app with a Deployment Target lower than 4.3 where armv6 support is required.

Answer 2

You should always use the latest SDK as Base SDK whenever possible. If you set the deployment target to a lower SDK, your app will run on device with previous SDK version.

Starting from XCode 4.5 (and also in XCode 5) iOS 4.3 is the lowest available SDK for deployment target. You have no way to submit new App on the App Store running on SDK lower than 4.3.

To answer the initial question, Apple seem to still accept application compiled with SDK 6.0 ( at least a few weeks ago).

Answer 3

Apple has recently announced that as of March 27, 2019, you will have to have a base SDK of 12.1:

Upcoming App Store Submission Requirements March 20, 2019

iOS 12 is now running on more than 80% of devices worldwide. Make sure your app delivers a great user experience by seamlessly integrating with the latest advances in iOS. Starting March 27, 2019, all new apps and app updates for iPhone or iPad, including universal apps, must be built with the iOS 12.1 SDK or later and support iPhone XS Max or the 12.9-inch iPad Pro (3rd generation). Screenshots for these devices will also be required. All new apps and app updates for Apple Watch will need to be built with the watchOS 5.1 SDK or later and support Apple Watch Series 4.

Understanding Changes in Memory Accounting iOS 12 and tvOS 12 require apps to use memory far more efficiently than before. If you have difficulty reducing your app’s memory requirements, contact us to request an entitlement for your app to use iOS 11-style memory accounting.