Apple shared the statistics on the App Store Developers page which was updated today. Apple reports that iOS 13 is installed on 55% of all iPhones introduced in the past four years, and 50% of all iPhone devices, as measured by App Store activity. The pace puts iOS 13 approximately on par with iOS 12 adoption last year which hit 53% of active devices in a slightly shorter timeframe and a different device breakdown.
This year, Apple has broken down the stats between both iOS 13 and iPadOS which were launched at different times this year. According to Apple, 41% of iPads from the past four years have upgraded to iPadOS, while 33% of all active iPads are on iPadOS.
Meanwhile, here on MacRumors, our analytics show an 84% iOS 13 adoption by our visitors on the same day that Apple measured — October 15th.