PunycodeSwift is a pure Swift library to allows you to encode and decode punycoded strings by using String extension.

Punycode is a representation of Unicode with the limited ASCII character subset used for Internet host names. Using Punycode, host names containing Unicode characters are transcoded to a subset of ASCII consisting of letters, digits, and hyphen, which is called the Letter-Digit-Hyphen (LDH) subset. For example, München (German name for Munich) is encoded as Mnchen-3ya. (Wikipedia)

• macOS 10.13 or later
• iOS 12.0 or later
• tvOS 12.0 or later
• watchOS 4.0 or later
• visionOS 1.0 or later
• Linux
• Swift 5.9 or later (Xcode 15 or later) for Swift Package Manager

Swift Package Manager is the recommended way to install PunycodeSwift.

Add the following to your Package.swift file.

• macOS, iOS, tvOS, watchOS, visionOS, Linux, and Swift 5.9 (Xcode 15) or later

  dependencies: [
      .package(url: "https://github.com/futamura/PunycodeSwift.git", .upToNextMajor(from: "4.0.0"))
  ]

• macOS, iOS, tvOS, watchOS, visionOS, and Swift 5

  dependencies: [
      .package(url: "https://github.com/futamura/PunycodeSwift.git", .upToNextMajor(from: "3.0.0"))
  ]

• macOS, iOS, tvOS, and Swift 5

  dependencies: [
      .package(url: "https://github.com/futamura/PunycodeSwift.git", .upToNextMajor(from: "2.1.1"))
  ]

Add the following to your Cartfile and follow these instructions.

• macOS, iOS, tvOS, watchOS, visionOS, and Swift 5.9 or later

  github "futamura/PunycodeSwift" ~> 4.0
  

• macOS, iOS, tvOS, watchOS, visionOS, and Swift 5

  github "futamura/PunycodeSwift" ~> 3.0
  

• macOS, iOS, tvOS, and Swift 5

  github "futamura/PunycodeSwift" ~> 2.0
  

• macOS, iOS, tvOS, and Swift 4

  github "futamura/PunycodeSwift" ~> 1.0
  

Existing installations reference the pod as follows.

• macOS, iOS, tvOS, watchOS, visionOS, and Swift 5.0

  pod 'Punycode', '~> 3.0'

• macOS, iOS, tvOS, and Swift 5.0

  pod 'Punycode', '~> 2.0'

• macOS, iOS, tvOS, and Swift 4.2

  pod 'Punycode', '~> 1.0'

Full documentation is available at https://futamura.github.io/PunycodeSwift/documentation/punycode/.

import Punycode

var sushi: String = "寿司"

sushi = sushi.idnaEncoded!
print(sushi)  // xn--sprr0q

sushi = sushi.idnaDecoded!
print(sushi)  // "寿司"

idnaEncoded expects a bare hostname. For a full URL, use idnaEncodedURL / idnaDecodedURL, which transform only the host and leave the scheme, userinfo, port, path, query, and fragment unchanged.

import Punycode

var url: String = "http://www.ラーメン.寿司.co.jp/メニュー"

url = url.idnaEncodedURL!
print(url)  // http://www.xn--4dkp5a8a.xn--sprr0q.co.jp/メニュー

url = url.idnaDecodedURL!
print(url)  // http://www.ラーメン.寿司.co.jp/メニュー

punycodeEncoded / punycodeDecoded are the raw RFC 3492 transformation of a single label: no xn-- prefix is added and dots are not treated as label separators.

import Punycode

var sushi: String = "寿司"

sushi = sushi.punycodeEncoded!
print(sushi)  // sprr0q

sushi = sushi.punycodeDecoded!
print(sushi)  // "寿司"

Punycode is released under MIT license, which means you can modify it, redistribute it or use it however you like.