Finally I solved this problem by adding an html string: For Objective-C: NSString *headerString = @”<head><meta name=”viewport” content=”width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=no”></head>”; [self.webView loadHTMLString:[headerString stringByAppendingString:yourHTMLString] baseURL:nil]; For Swift: let headerString = “<head><meta name=”viewport” content=”width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=no”></head>” webView.loadHTMLString(headerString + yourHTMLString, baseURL: nil) What’s more,if you want to load url rather than html you can … Read more