Change character spacing on UILabel within Interface Builder

Is there anyway to change the character spacing (track) on UILabel text using Interface Builder? If not, is there a way to do it programmatically on an existing UILabel that was already created with attributed text?

I know it's not an Interface Builder solution, but you can create a UILabel extension and then add spacing to any UILabel you want:

extension UILabel {
  func addCharacterSpacing(kernValue: Double = 1.15) {
    guard let text = text, !text.isEmpty else { return }
    let string = NSMutableAttributedString(string: text)
    string.addAttribute(NSAttributedString.Key.kern, value: kernValue, range: NSRange(location: 0, length: string.length - 1))
    attributedText = string
  }
}

Consider changing the default kernValue from 1.15 to something that works better with your design.

---

When implementing always add character spacing after setting the text value:

myLabel.text = "We used to be so close"
myLabel.addCharacterSpacing()

If you plan to have different spacing at different places in the app, you can override the default kern value:

myLabelWithSpecialNeeds.addCharacterSpacing(kernValue: 1.3)

---

This solution overrides any other attributes you might have on your UILabel's attributedText.

Ended up using this for now to get existing attributed text and modify to add character spacing:

let attributedString = discoveryTitle.attributedText as NSMutableAttributedString
attributedString.addAttribute(NSKernAttributeName, value: 1.0, range: NSMakeRange(0, attributedString.length))
discoveryTitle.attributedText = attributedString

Swift 3:

let attributedString = NSMutableAttributedString(string: discoveryTitle.text)
attributedString.addAttribute(NSKernAttributeName, value: CGFloat(1.0), range: NSRange(location: 0, length: attributedString.length))
discoveryTitle.attributedText = attributedString

Using NSRange instead of NSMakeRange works in Swift 3.

For completely static text, like the header of a view or especially the launchScreen, you can insert letters that take up a tiny amount of width (e.g. the 'l' character) with 0 opacity. Alternatively set its color to the same as background.

I am aware of the fact, that is not the prettiest solution, but it is the only solution that works without writing any code and does the job - until you can do it by specifying the attributes in Xcode.

Edit / Additional idea: To make your spacing even more variable you can change the font size of the filling charachters in between. (Thanks to @mohamede1945 for that idea)

Swift 3.2 & Interface builder

extension UILabel {

    @IBInspectable
    var letterSpace: CGFloat {
        set {
            let attributedString: NSMutableAttributedString!
            if let currentAttrString = attributedText {
                attributedString = NSMutableAttributedString(attributedString: currentAttrString)
            }
            else {
                attributedString = NSMutableAttributedString(string: text ?? "")
                text = nil
            }

            attributedString.addAttribute(NSKernAttributeName,
                                           value: newValue,
                                           range: NSRange(location: 0, length: attributedString.length))

            attributedText = attributedString
        }

        get {
            if let currentLetterSpace = attributedText?.attribute(NSKernAttributeName, at: 0, effectiveRange: .none) as? CGFloat {
                return currentLetterSpace
            }
            else {
                return 0
            }
        }
    }
}

Swift 5 and higher

extension UILabel {
  func setTextSpacingBy(value: Double) {
    if let textString = self.text {
      let attributedString = NSMutableAttributedString(string: textString)
      attributedString.addAttribute(NSKernAttributeName, value: value, range: NSRange(location: 0, length: attributedString.length - 1))
      attributedText = attributedString
    }
  }
}

try this!!

create CustomLabel class

@interface CustomLabel : UILabel
@property (assign, nonatomic) CGFloat myLineSpacing;
@end


@implementation CustomLabel

- (void)setMyLineSpacing:(CGFloat)myLineSpacing {
    _myLineSpacing = myLineSpacing;
    self.text = self.text;
}

- (void)setText:(NSString *)text {
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.lineSpacing = _myLineSpacing;
    paragraphStyle.alignment = self.textAlignment;
    NSDictionary *attributes = @{NSParagraphStyleAttributeName: paragraphStyle};
    NSAttributedString *attributedText = [[NSAttributedString alloc] initWithString:text
                                                                         attributes:attributes];
    self.attributedText = attributedText;
}

and set runtime attribute

Note this is actually line spacing (also called leading .. in the very old days (pre-digital) you'd put lead (the metal) between lines to increase the gap between lines. For spacing between letters, that is called kerning .. here's how to do kerning https://stackoverflow.com/a/21141156/294884

Why all of you are defining NSMUTABLEAttributedString. You don't have to set range explicitly. It makes emojis looks weird sometimes. This is my solution, tested in Swift 4. 

extension UILabel {
    func addCharactersSpacing(_ value: CGFloat = 1.15) {
        if let textString = text {
            let attrs: [NSAttributedStringKey : Any] = [.kern: value]
            attributedText = NSAttributedString(string: textString, attributes: attrs)
        }
    }
}

SWIFT 4 UILabel extension:

import UIKit

extension UILabel {
    
    @IBInspectable
    var letterSpace: CGFloat {
        set {
            let attributedString: NSMutableAttributedString!
            if let currentAttrString = attributedText {
                attributedString = NSMutableAttributedString(attributedString: currentAttrString)
            } else {
                attributedString = NSMutableAttributedString(string: text ?? "")
                text = nil
            } 
            attributedString.addAttribute(NSAttributedString.Key.kern,
                                          value: newValue,
                                          range: NSRange(location: 0, length: attributedString.length))
            attributedText = attributedString
        }
        
        get {
            if let currentLetterSpace = attributedText?.attribute(NSAttributedString.Key.kern, at: 0, effectiveRange: .none) as? CGFloat {
                return currentLetterSpace
            } else {
                return 0
            }
        }
    }
}

Here is a solution for Swift 4 that won't override existing text attributes:

extension UILabel {
    
    /**
     Add kerning to a UILabel's existing `attributedText`
     - note: If `UILabel.attributedText` has not been set, the `UILabel.text`
     value will be returned from `attributedText` by default
     - note: This method must be called each time `UILabel.text` or
     `UILabel.attributedText` has been set
     - parameter kernValue: The value of the kerning to add
     */
    func addKern(_ kernValue: CGFloat) {
        guard let attributedText = attributedText,
            attributedText.string.count > 0,
            let fullRange = attributedText.string.range(of: attributedText.string) else {
                return
        }
        let updatedText = NSMutableAttributedString(attributedString: attributedText)
        updatedText.addAttributes([
            .kern: kernValue
            ], range: NSRange(fullRange, in: attributedText.string))
        self.attributedText = updatedText
    }
}

You can use the following Swift 4 UILabel extension which considers both existing attributed text and plain text in order to do not override the existing settings:

import UIKit

extension UILabel {
    func addCharacterSpacing(_ kernValue: Double = 1.30) {
        guard let attributedString: NSMutableAttributedString = {
            if let text = self.text, !text.isEmpty {
                return NSMutableAttributedString(string: text)
            } else if let attributedText = self.attributedText {
                return NSMutableAttributedString(attributedString: attributedText)
            }
            return nil
            }() else { return}

        attributedString.addAttribute(
            NSAttributedString.Key.kern,
            value: kernValue,
            range: NSRange(location: 0, length: attributedString.length)
        )
        self.attributedText = attributedString
    }
}

Here is my code for letter spacing. Create custom label class and set letter spacing from storyboard. Swift 5.

import UIKit

class SpacingLabel: UILabel {

    @IBInspectable
    var letterSpacing: Double = 0

    override public var text: String? {
        didSet {
            self.addCharacterSpacing(letterSpacing)
        }
    }

    func addCharacterSpacing(_ kernValue: Double) {
        if let labelText = text, labelText.count > 0 {
            let attributedString = NSMutableAttributedString(string: labelText)
            attributedString.addAttribute(NSAttributedString.Key.kern, value: kernValue, range: NSRange(location: 0, length: attributedString.length - 1))
            attributedText = attributedString
        }
    }
}

Try this. It will add the character spacing you assign, either you set simple text or attributed text.

open class UHBCustomLabel : UILabel {
    @IBInspectable open var characterSpacing:CGFloat = 1 {
        didSet {
            updateWithSpacing()
        }
        
    }

    open override var text: String? {
        set {
            super.text = newValue
            updateWithSpacing()
        }
        get {
            return super.text
        }
    }
    open override var attributedText: NSAttributedString? {
        set {
            super.attributedText = newValue
            updateWithSpacing()     
        }
        get {
            return super.attributedText
        }
    }
    func updateWithSpacing() {
        let attributedString = self.attributedText == nil ? NSMutableAttributedString(string: self.text ?? "") : NSMutableAttributedString(attributedString: attributedText!)
        attributedString.addAttribute(NSKernAttributeName, value: self.characterSpacing, range: NSRange(location: 0, length: attributedString.length))
        super.attributedText = attributedString
    }
}

Programming approach. (Try this, it should work for you)
Note: I tested in Swift 4

let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40

// Line spacing attribute
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: style, range: NSRange(location: 0, length: stringValue.characters.count))

// Character spacing attribute
attrString.addAttribute(NSAttributedStringKey.kern, value: 2, range: NSMakeRange(0, attrString.length))

label.attributedText = attrString

Swift 5.3.1

extension UILabel {
  func addCharacterSpacing(kernValue: Double = 1.15) {
    if let labelText = text, labelText.count > 0 {
      let attributedString = NSMutableAttributedString(string: labelText)
        attributedString.addAttribute(NSAttributedString.Key.kern, value: kernValue, range: NSRange(location: 0, length: attributedString.length - 1))
      attributedText = attributedString
    }
  }
}