NEW! Master Swift design patterns with my latest book! >>

What's the difference between UIWebView and WKWebView?

Paul Hudson       @twostraws

The UIWebView class has been around since iOS 2.0 as a way to show HTML content inside your app, but iOS 8.0 introduced WKWebView as an alternative - what's the difference?

Well, there are several differences, but two are particularly important. First, UIWebView is part of UIKit, and thus is available to your apps as standard. You don't need to import anything – it's just there. This also means it's available inside Interface Builder, so you can drag and drop web view into your designs.

Second, WKWebView is run in a separate process to your app so that it can draw on native Safari JavaScript optimizations. This means WKWebView loads web pages faster and more efficiently than UIWebView, and also doesn't have as much memory overhead for you.

In iOS 8.0 WKWebView was unable to load local files, but this got fixed in iOS 9.0. The main reason to use UIWebView nowadays is for access to older features such as "Scale pages to fit" - this is not available in WKWebView.

Available from iOS 8.0 – see Hacking with Swift tutorial 4

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Become a Swift expert

I wrote a book called Pro Swift that's dedicated to helping you master the Swift language, and it includes seven hours of video demonstrating each technique!

MASTER SWIFT NOW
Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Practical iOS 11 Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Click here to visit the Hacking with Swift store >>