How to increase the character spacing in UILabel

Swift extension for this

extension UILabel {
    func addCharactersSpacing(spacing:CGFloat, text:String) {
        let attributedString = NSMutableAttributedString(string: text)
        attributedString.addAttribute(NSAttributedString.Key.kern, value: spacing, range: NSMakeRange(0, text.count-1))
        self.attributedText = attributedString
    }
}

So you can use it

MyLabel.addCharactersSpacing(5, text: "Some Text")

Swift 4

extension UILabel {

   func setCharacterSpacing(characterSpacing: CGFloat = 0.0) {

        guard let labelText = text else { return }

        let attributedString: NSMutableAttributedString
        if let labelAttributedText = attributedText {
            attributedString = NSMutableAttributedString(attributedString: labelAttributedText)
        } else {
            attributedString = NSMutableAttributedString(string: labelText)
        }

        // Character spacing attribute
        attributedString.addAttribute(NSAttributedStringKey.kern, value: characterSpacing, range: NSMakeRange(0, attributedString.length))

        attributedText = attributedString
    }        

}

Swift 3

let label = UILabel()
let stringValue = "Sample text"
let attrString = NSMutableAttributedString(string: stringValue)
attrString.addAttribute(NSKernAttributeName, 2: style, range: NSRange(location: 0, length: stringValue.characters.count))
label.attributedText = attrString

Here the code for Swift 5 with a handy extension :

extension UILabel {
    func addCharactersSpacing(spacing: CGFloat, txt: String) {
        let attributedString = NSMutableAttributedString(string: txt)
        attributedString.addAttribute(NSAttributedString.Key.kern, value: spacing, range: NSRange(location: 0, length: txt.count))
        self.attributedText = attributedString
    }
}

You should probably use NSAttributedString with NSKernAttributeName attribute

Here is a small example:

UILabel *label = [[UILabel alloc] initWithFrame:self.view.bounds];

NSString *string = @"Some important text";
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:string];

float spacing = 5.0f;
[attributedString addAttribute:NSKernAttributeName
            value:@(spacing)
            range:NSMakeRange(0, [string length])];

label.attributedText = attributedString;
[self.view addSubview:label];