Is UIWebview JS Performance slower than mobile safari on iOS 6/7?

Question

We have recently tested some HTML5 content with heavy javascript libraries from an iOS app. The app designed to load these contents in UIWebview. iOS 6 was used for this testing. My team did not observe any noticeable performance issues against mobile safari browser. But on the web and in other stackoverflow discussions (like this one - link) experts claim that UIWebview misses Nitro Javascript Engine so it is usually much slower than Mobile Safari Browser.

Is this no longer an issue with the latest versions of iOS (6/7 beta)?

Is there a way to benchmark and observe the performance difference between UIWebview and Mobile Safari Browser?

Answer 1

Yes there is a way to benchmark the differences.

Start this benchmark in Safari first: http://www.webkit.org/perf/sunspider/sunspider.html

Then, build a simple app that contains an UIWebView and let it open the URL. Now start the App on your Tablet/Phone an run the test again in your UIWebView.

My results on iPad 2 iOS 6.1.3:

Safari Total: 1490.8ms

UIWebView Total: 5496.8ms