Is there a way to know if an Emoji is supported in iOS?

Clarification: an Emoji is merely a character in the Unicode Character space, so the present solution works for all characters, not just Emoji.

Synopsis

To know if a Unicode character (including an Emoji) is available on a given device or OS, run the unicodeAvailable() method below.

It works by comparing a given character image against a known undefined Unicode character U+1FFF.

unicodeAvailable(), a Character extension

private static let refUnicodeSize: CGFloat = 8private static let refUnicodePng =    Character("\u{1fff}").png(ofSize: Character.refUnicodeSize)func unicodeAvailable() -> Bool {    if let refUnicodePng = Character.refUnicodePng,        let myPng = self.png(ofSize: Character.refUnicodeSize) {        return refUnicodePng != myPng    }    return false}

Discussion

1. All characters will be rendered as a png at the same size (8) as defined once in

   static let refUnicodeSize: CGFloat = 8

2. The undefined character U+1FFF image is calculated once in

   static let refUnicodePng = Character("\u{1fff}").png(ofSize: Character.refUnicodeSize)

3. A helper method optionally creates a png from a Character

   func png(ofSize fontSize: CGFloat) -> Data?

1. Example: Test against 3 emoji

let codes:[Character] = ["\u{2764}","\u{1f600}","\u{1F544}"] // ❤️, 😀, undefinedfor unicode in codes {    print("\(unicode) : \(unicode.unicodeAvailable())")}

2. Example: Test a range of Unicode characters

func unicodeRange(from: Int, to: Int) {    for unicodeNumeric in from...to {        if let scalar = UnicodeScalar(unicodeNumeric) {            let unicode = Character(scalar)            let avail = unicode.unicodeAvailable()            let hex = String(format: "0x%x", unicodeNumeric)            print("\(unicode) \(hex) is \(avail ? "" : "not ")available")        }    }}

Helper function: Character to png

func png(ofSize fontSize: CGFloat) -> Data? {    let attributes = [NSAttributedStringKey.font:                          UIFont.systemFont(ofSize: fontSize)]    let charStr = "\(self)" as NSString    let size = charStr.size(withAttributes: attributes)    UIGraphicsBeginImageContext(size)    charStr.draw(at: CGPoint(x: 0,y :0), withAttributes: attributes)    var png:Data? = nil    if let charImage = UIGraphicsGetImageFromCurrentImageContext() {        png = UIImagePNGRepresentation(charImage)    }    UIGraphicsEndImageContext()    return png}

► Find this solution on GitHub and a detailed article on Swift Recipes.

Just for future reference, after discovering my app had 13.2 emojis not supported in 12.x versions, I used the answer from here: How can I determine if a specific emoji character can be rendered by an iOS device? which worked really well for me.