Carthage compatible CocoaPods Platform Reviewed by Hound

    SwiftyJSON makes it easy to deal with JSON data in Swift.

    Platform Build Status
    *OS Travis CI
    Linux Build Status
    1. Why is the typical JSON handling in Swift NOT good
    2. Requirements
    3. Integration
    4. Usage
    5. Work with Alamofire
    6. Work with Moya
    7. SwiftyJSON Model Generator

    Why is the typical JSON handling in Swift NOT good?

    Swift is very strict about types. But although explicit typing is good for saving us from mistakes, it becomes painful when dealing with JSON and other areas that are, by nature, implicit about types.

    Take the Twitter API for example. Say we want to retrieve a user's "name" value of some tweet in Swift (according to Twitter's API).

    The code would look like this:

    if let statusesArray = try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [[String: Any]],
        let user = statusesArray[0]["user"] as? [String: Any],
        let username = user["name"] as? String {
        // Finally we got the username

    It's not good.

    Even if we use optional chaining, it would be messy:

    if let JSONObject = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [[String: Any]],
        let username = (JSONObject[0]["user"] as? [String: Any])?["name"] as? String {
            // There's our username

    An unreadable mess--for something that should really be simple!

    With SwiftyJSON all you have to do is:

    let json = JSON(data: dataFromNetworking)
    if let userName = json[0]["user"]["name"].string {
      //Now you got your value

    And don't worry about the Optional Wrapping thing. It's done for you automatically.

    let json = JSON(data: dataFromNetworking)
    let result = json[999999]["wrong_key"]["wrong_name"]
    if let userName = result.string {
        //Calm down, take it easy, the ".string" property still produces the correct Optional String type with safety
    } else {
        //Print the error


    • iOS 8.0+ | macOS 10.10+ | tvOS 9.0+ | watchOS 2.0+
    • Xcode 8


    CocoaPods (iOS 8+, OS X 10.9+)

    You can use CocoaPods to install SwiftyJSON by adding it to your Podfile:

    platform :ios, '8.0'
    target 'MyApp' do
        pod 'SwiftyJSON', '~> 4.0'

    Carthage (iOS 8+, OS X 10.9+)

    You can use Carthage to install SwiftyJSON by adding it to your Cartfile:

    github "SwiftyJSON/SwiftyJSON" ~> 4.0

    If you use Carthage to build your dependencies, make sure you have added SwiftyJSON.framework to the "Linked Frameworks and Libraries" section of your target, and have included them in your Carthage framework copying build phase.

    Swift Package Manager

    You can use The Swift Package Manager to install SwiftyJSON by adding the proper description to your Package.swift file:

    // swift-tools-version:4.0
    import PackageDescription
    let package = Package(
        name: "YOUR_PROJECT_NAME",
        dependencies: [
            .package(url: "", from: "4.0.0"),

    Then run swift build whenever you get prepared.

    Manually (iOS 7+, OS X 10.9+)

    To use this library in your project manually you may:

    1. for Projects, just drag SwiftyJSON.swift to the project tree
    2. for Workspaces, include the whole SwiftyJSON.xcodeproj



    import SwiftyJSON
    let json = JSON(data: dataFromNetworking)


    let json = JSON(jsonObject)


    if let dataFromString = .utf8, allowLossyConversion: false) {
        let json = JSON(data: dataFromString)


    // Getting a double from a JSON Array
    let name = json[0].double
    // Getting an array of string from a JSON Array
    let arrayNames =  json["users"] {$0["name"].stringValue}
    // Getting a string from a JSON Dictionary
    let name = json["name"].stringValue
    // Getting a string using a path to the element
    let path: [JSONSubscriptType] = [1,"list",2,"name"]
    let name = json[path].string
    // Just the same
    let name = json[1]["list"][2]["name"].string
    // Alternatively
    let name = json[1,"list",2,"name"].string
    // With a hard way
    let name = json[].string
    // With a custom way
    let keys:[JSONSubscriptType] = [1,"list",2,"name"]
    let name = json[keys].string


    // If json is .Dictionary
    for (key,subJson):(String, JSON) in json {
       // Do something you want

    The first element is always a String, even if the JSON is an Array

    // If json is .Array
    // The `index` is 0..<json.count's string value
    for (index,subJson):(String, JSON) in json {
        // Do something you want


    SwiftyJSON 4.x

    SwiftyJSON 4.x introduces an enum type called SwiftyJSONError, which includes unsupportedType, indexOutOfBounds, elementTooDeep, wrongType, notExist and invalidJSON, at the same time, ErrorDomain are being replaced by SwiftyJSONError.errorDomain. Note: Those old error types are deprecated in SwiftyJSON 4.x and will be removed in the future release.

    SwiftyJSON 3.x

    Use a subscript to get/set a value in an Array or Dictionary

    If the JSON is:

    • an array, the app may crash with "index out-of-bounds."
    • a dictionary, it will be assigned to nil without a reason.
    • not an array or a dictionary, the app may crash with an "unrecognised selector" exception.

    This will never happen in SwiftyJSON.

    let json = JSON(["name", "age"])
    if let name = json[999].string {
        // Do something you want
    } else {
        print(json[999].error!) // "Array[999] is out of bounds"
    let json = JSON(["name":"Jack", "age": 25])
    if let name = json["address"].string {
        // Do something you want
    } else {
        print(json["address"].error!) // "Dictionary["address"] does not exist"
    let json = JSON(12345)
    if let age = json[0].string {
        // Do something you want
    } else {
        print(json[0])       // "Array[0] failure, It is not an array"
        print(json[0].error!) // "Array[0] failure, It is not an array"
    if let name = json["name"].string {
        // Do something you want
    } else {
        print(json["name"])       // "Dictionary[\"name"] failure, It is not an dictionary"
        print(json["name"].error!) // "Dictionary[\"name"] failure, It is not an dictionary"

    Optional getter

    // NSNumber
    if let id = json["user"]["favourites_count"].number {
       // Do something you want
    } else {
       // Print the error
    // String
    if let id = json["user"]["name"].string {
       // Do something you want
    } else {
       // Print the error
    // Bool
    if let id = json["user"]["is_translator"].bool {
       // Do something you want
    } else {
       // Print the error
    // Int
    if let id = json["user"]["id"].int {
       // Do something you want
    } else {
       // Print the error

    Non-optional getter

    Non-optional getter is named xxxValue

    // If not a Number or nil, return 0
    let id: Int = json["id"].intValue
    // If not a String or nil, return ""
    let name: String = json["name"].stringValue
    // If not an Array or nil, return []
    let list: Array<JSON> = json["list"].arrayValue
    // If not a Dictionary or nil, return [:]
    let user: Dictionary<String, JSON> = json["user"].dictionaryValue


    json["name"] = JSON("new-name")
    json[0] = JSON(1)
    json["id"].int =  1234567890
    json["coordinate"].double =  8766.766
    json["name"].string =  "Jack"
    json.arrayObject = [1,2,3,4]
    json.dictionaryObject = ["name":"Jack", "age":25]

    Raw object

    let rawObject: Any = json.object
    let rawValue: Any = json.rawValue
    //convert the JSON to raw NSData
    do {
    	let rawData = try json.rawData()
      //Do something you want
    } catch {
    	print("Error \(error)")
    //convert the JSON to a raw String
    if let rawString = json.rawString() {
      //Do something you want
    } else {
    	print("json.rawString is nil")


    // shows you whether value specified in JSON or not
    if json["name"].exists()

    Literal convertibles

    For more info about literal convertibles: Swift Literal Convertibles

    // StringLiteralConvertible
    let json: JSON = "I'm a json"
    / /IntegerLiteralConvertible
    let json: JSON =  12345
    // BooleanLiteralConvertible
    let json: JSON =  true
    // FloatLiteralConvertible
    let json: JSON =  2.8765
    // DictionaryLiteralConvertible
    let json: JSON =  ["I":"am", "a":"json"]
    // ArrayLiteralConvertible
    let json: JSON =  ["I", "am", "a", "json"]
    // With subscript in array
    var json: JSON =  [1,2,3]
    json[0] = 100
    json[1] = 200
    json[2] = 300
    json[999] = 300 // Don't worry, nothing will happen
    // With subscript in dictionary
    var json: JSON =  ["name": "Jack", "age": 25]
    json["name"] = "Mike"
    json["age"] = "25" // It's OK to set String
    json["address"] = "L.A." // Add the "address": "L.A." in json
    // Array & Dictionary
    var json: JSON =  ["name": "Jack", "age": 25, "list": ["a", "b", "c", ["what": "this"]]]
    json["list"][3]["what"] = "that"
    json["list",3,"what"] = "that"
    let path: [JSONSubscriptType] = ["list",3,"what"]
    json[path] = "that"
    // With other JSON objects
    let user: JSON = ["username" : "Steve", "password": "supersecurepassword"]
    let auth: JSON = [
      "user": user.object, // use user.object instead of just user
      "apikey": "supersecretapitoken"


    It is possible to merge one JSON into another JSON. Merging a JSON into another JSON adds all non existing values to the original JSON which are only present in the other JSON.

    If both JSONs contain a value for the same key, mostly this value gets overwritten in the original JSON, but there are two cases where it provides some special treatment:

    • In case of both values being a JSON.Type.array the values form the array found in the other JSON getting appended to the original JSON's array value.
    • In case of both values being a JSON.Type.dictionary both JSON-values are getting merged the same way the encapsulating JSON is merged.

    In a case where two fields in a JSON have different types, the value will get always overwritten.

    There are two different fashions for merging: merge modifies the original JSON, whereas merged works non-destructively on a copy.

    let original: JSON = [
        "first_name": "John",
        "age": 20,
        "skills": ["Coding", "Reading"],
        "address": [
            "street": "Front St",
            "zip": "12345",
    let update: JSON = [
        "last_name": "Doe",
        "age": 21,
        "skills": ["Writing"],
        "address": [
            "zip": "12342",
            "city": "New York City"
    let updated = original.merge(with: update)
    // [
    //     "first_name": "John",
    //     "last_name": "Doe",
    //     "age": 21,
    //     "skills": ["Coding", "Reading", "Writing"],
    //     "address": [
    //         "street": "Front St",
    //         "zip": "12342",
    //         "city": "New York City"
    //     ]
    // ]

    String representation

    There are two options available:

    • use the default Swift one
    • use a custom one that will handle optionals well and represent nil as "null":
    let dict = ["1":2, "2":"two", "3": nil] as [String: Any?]
    let json = JSON(dict)
    let representation = json.rawString(options: [.castNilToNSNull: true])
    // representation is "{\"1\":2,\"2\":\"two\",\"3\":null}", which represents {"1":2,"2":"two","3":null}

    Work with Alamofire

    SwiftyJSON nicely wraps the result of the Alamofire JSON response handler:

    Alamofire.request(url, method: .get).validate().responseJSON { response in
        switch response.result {
        case .success(let value):
            let json = JSON(value)
            print("JSON: \(json)")
        case .failure(let error):

    We also provide an extension of Alamofire for serializing NSData to SwiftyJSON's JSON.

    See: Alamofire-SwiftyJSON

    Work with Moya

    SwiftyJSON parse data to JSON:

    let provider = MoyaProvider<Backend>()
    provider.request(.showProducts) { result in
        switch result {
        case let .success(moyaResponse):
            let data =
            let json = JSON(data: data) // convert network data to json
        case let .failure(error):
            print("error: \(error)")

    SwiftyJSON Model Generator

    Tools to generate SwiftyJSON Models


    🚀 Github 镜像仓库 🚀


    发行版本 21

    Swift 5.0


    贡献者 152



    • Swift 98.7 %
    • Objective-C 0.9 %
    • Ruby 0.4 %