iOS 8 WebKit changes finally allow all apps to have the same performance as Safari
When iOS 7 launched, developers discovered that their apps with built-in web browsers were unable to achieve the same level of JavaScript performance as the stock Safari app. This was because Apple restricted use of its improved Nitro JavaScript engine to its own app, leaving third-parties with a slower version.
A few teasers: API is the same across iOS and OS X, and the new WKWebView on iOS is running JS just as quickly as Safari.
— Vicki Murley (@vickimurley) June 3, 2014
As of iOS 8, however, it seems that decision has been reversed. All apps will now be able to use the same improved JavaScript engine that powers Safari. That means Google’s Chrome browser on iOS will now be just as quick as Safari, as will the pop-up browsers embedded in apps like Twitter and Facebook.