Don’t forget to import the necessary framework first.

import SafariServices
//Objective-C
@import SafariServices;

Instantiate a SafariViewController instance.

let safariVC = SFSafariViewController(URL: URL(string: "your_url")!)
//Objective-C
@import SafariServices;
NSURL *URL = [NSURL URLWithString:[NSString stringWithFormat:@"<http://www.google.com>"]];
SFSafariViewController *sfvc = [[SFSafariViewController alloc] initWithURL:URL];

Optionally you can also tell SafariViewController to enter reading mode if possible once it’s done loading.

let safariVC = SFSafariViewController(URL: URL(string: "your_url")!, entersReaderIfAvailable: true)
//Objective-C
NSURL *URL = [NSURL URLWithString:[NSString stringWithFormat:@"<http://www.google.com>"]];
SFSafariViewController *sfvc = [[SFSafariViewController alloc] initWithURL:URL entersReaderIfAvailable:YES];

Present the view controller.

present(safariVC, animated: true, completion: nil)
//Objective-C
[self presentViewController:sfvc animated:YES completion:nil];