UIWebView VS WKWebView to load local html

Question

i create a html string with 500 p tag with timestamp in it

i use UIWebView and WKWebView loadHTMLString:baseURL: to load it,and wkWebView is slower about 50% than UIWebVIew . why?

UIWebView:0.1681529879570007
WKWebView:0.3913570046424866

Answer 1

WKWebView is faster for displaying html from Strings. However, there is a bug that makes UIWebView faster by default, which is the phone number detection.

Running a viewController with the following code, webView being respectively a UIWebView and WKWebView instance and keeping everything else identical I found WKWebView to take up to 2 seconds to load, while UIWebView loads almost instantly.

webView.loadHTMLString(HtmlStringInstance, baseURL: nil)

I'm by far not the only one to find this:

• when I use wkwebview to load local html,I find it renders slower than uiwebview
• UIWebView delay in loading local content
• Slow loading UIWebView from string
• Delay in loading a HTML string into a UIWebView
• Why UIWebView work so slowly when loadHTMLString with UIWebView?

However, the solution is easy: Disable phone number detection for WKWebView and poof. There you go.

Answer 2

For me, creating static variable to avoid creating WKWebView multiple times worked. Objective-C example:

- (WKWebView *)webHeaderView
{
    static WKWebView *_webHeaderView = nil;
    static dispatch_once_t onceToken;

    dispatch_once(&onceToken, ^{
        if (!_webHeaderView)
        {
            WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
            _webHeaderView = [[WKWebView alloc] initWithFrame:CGRectZero configuration:configuration];
        }
    });

    return _webHeaderView;
}

Answer 3

WKWebView rendering performance is noticeable in WebGL games and something that runs complex JavaScript algorithms which UIWebView lacks.

You check the performance both in the Github .

Answer 4

To make WKWebView faster, disabling WKWebView's data detectors worked for me. Swift version:

let webViewCofig = WKWebViewConfiguration()
webViewCofig.dataDetectorTypes = []
webView = WKWebView(frame: view.frame, configuration: webViewCofig)

To enable specific data detector, pass the specific type as .address,.link etc while setting dataDetectorTypes:

config.dataDetectorTypes = [.address]