iOS10.2.1 Beta 4 has been released to developers and public tester for a while. Does 10.2.1 bring any major performance improvements to the table?

To find out, iAppleBytes team from Youtube has tested on 4 iPhone models including iPhone 6s,iPhone 6,iPhone 5s and iPhone5 ,total 8 devices using same models on different iOS to test. 

They tested on boot time /application opening time on iPhone to test system operate speed. Although activated iPhone 5s with iOS 10.2.1 Beta4 is slower than iPhone 5s with iOS 10.2. The test result has shown there is no significant performance differences on other iOS devices.

What's more, there is no difference on activating time, browsing and UI features between iOS 10.2 and iOS 10.2.1 Beta4.

Recently rumors have leaked that iOS 10.2.1 official version will come out soon, if you are interested in latest iOS, you can update through OTA or in 3uTools.

Here also have 2 videos（iPhone 6s and iPhone 5) in test process for your reference.