Why Third-Party browsers, Including Chrome, are Slower Than the Default Safari in iOS
Most people have a favorite browser that they like to use on all of their devices, whether it be Google Chrome, Mozilla Firefox, or Internet Explorer. Unfortunately for iOS users, Apple does not currently appear to be concerned about your web browsing preferences, and it doesn't appear that they'll begin to care any time soon.
Apple's own Safari app is the native web browser on the iOS operating system, and although it is not a bad browser on any device or operating system, for some reason it is always faster than any other browser within iOS. Many people are confused as to why no other browser can load pages as fast as Safari on their iPhone or iPad when their PC loads pages faster in Chrome. The answers may actually surprise you...
All Browsers in iOS Must Use the Safari Rendering Engine
If you take a look at the policy in the Apple App Store regarding this issue, there is a clause that states all apps must utilize the iOS WebKit framework and WebKit Javascript. In other words, web browsers like Chrome can't use their own rendering engines to display pages. Instead, they have to use the same technology that displays pages within Safari. This essentially makes every other browser used in iOS a clone built completely around the Safari engine, and this is why no other browser can possibly perform better than Safari within iOS. In other operating systems like Windows, Linux, and MAC OSX, all browsers can make use of their own rendering engines, which is why there are often measurable difference in page load times and other attributes when comparing multiple browsers on a PC. Many developers are disgruntled about this issue, and the CEO of Mozilla Firefox has even stated that they refuse to bring Firefox to iOS until they're allowed to use their own web engine, which is why there is no version of Firefox available for iOS.
Plus... Safari is Equipped With Special Javascript that iOS Will Not Let Other Browsers Use!
In addition to forcing all browsers to use Safari's rendering engine within iOS, Apple has also equipped Safari with the new “Nitro Javascript” engine, while forcing all other browsers to use the standard WebKit Javascript engine. This gives Safari a speed advantage that cannot be circumvented. As Apple continues to develop the Nitro Javascript engine, Safari will get faster while all other browsers will be forced to stay using the conventional Javascript WebKit within iOS.
You Can Only Make Safari Your Default Browser
Since iOS does not let you choose your default apps, you could never set Google Chrome or Internet Explorer as your default browser; Safari will always be the browser that launches when you decide to view a web page or click a link on your iPad or iPhone. However, in many apps there are options that let you choose which browser you'd like to use when accessing the web within the app, so that is one potential workaround.
No Add-Ons for Non-Safari Browsers
As if the above restrictions aren't totalitarian enough, Apple basically strips the value from all competing browsers by not allowing them to use add-ons. So all of those cool extras that make Chrome so convenient on your PC or Mac are completely nonexistent in the iOS operating system.