Json.NET vs Windows.Data.Json

Windows 8 introduces a new way to work with JSON via the Windows.Data.Json namespace. Similar to LINQ to JSON in Json.NET it defines classes that can be used to parse values, strings, objects, and arrays from JSON text or serialize value types into JSON text.

Below is a comparison of Json.NET’s LINQ to JSON to Window 8’s Windows.Data.Json.

Creating JSON

The big difference between the two libraries when creating JSON is Windows.Data.Json requires string/integer/double values to be explicitly converted to JsonValue objects.

Note that there is a weird limitation to creating JSON with Windows.Data.Json: it doesn’t allow you to set properties to null or have null array values.

// Windows.Data.Json
// -----------------
JsonObject jsonObject = new JsonObject
    {"CPU", JsonValue.CreateStringValue("Intel")},
    {"Drives", new JsonArray {
        JsonValue.CreateStringValue("DVD read/writer"),
        JsonValue.CreateStringValue("500 gigabyte hard drive")
string json1 = jsonObject.Stringify();
// ------------
JObject jObject = new JObject
    {"CPU", "Intel"},
    {"Drives", new JArray {
        "DVD read/writer",
        "500 gigabyte hard drive"
string json2 = jObject.ToString();

Querying JSON

Windows.Data.Json requires a value to be cast to its exact type with the GetObject/GetArray methods before it can be used, making Windows.Data.Json’s code verbose compared to LINQ to JSON.

string json = @"{
  ""channel"": {
    ""title"": ""James Newton-King"",
    ""link"": ""http://james.newtonking.com"",
    ""description"": ""James Newton-King's blog."",
    ""item"": [
        ""title"": ""Json.NET 1.3 + New license + Now on CodePlex"",
        ""description"": ""Annoucing the release of Json.NET 1.3, the MIT license and the source being available on CodePlex"",
        ""link"": ""http://james.newtonking.com/projects/json-net.aspx"",
        ""category"": [
// Windows.Data.Json
// -----------------
JsonObject jsonObject = JsonObject.Parse(json);
string itemTitle1 = jsonObject["channel"].GetObject()["item"].GetArray()[0].GetObject()["title"].GetString();
// ------------
JObject jObject = JObject.Parse(json);
string itemTitle2 = (string)jObject["channel"]["item"][0]["title"];


Json.NET is slightly slower at writing JSON than Windows.Data.Json but considerably faster parsing.

Things aren’t as happy as they used to be down here at the unemployment office. Joblessness is no longer just for philosophy majors. Useful people are starting to feel the pinch.

Converting Between LINQ to JSON and Windows.Data.Json

Json.NET supports converting between the types of the two libraries. Use FromObject to convert a Windows.Data.Json value to LINQ to JSON and use ToObject to convert LINQ to JSON to Windows.Data.Json.

JsonObject jsonObject = new JsonObject
    {"CPU", JsonValue.CreateStringValue("Intel")},
    {"Drives", new JsonArray {
        JsonValue.CreateStringValue("DVD read/writer"),
        JsonValue.CreateStringValue("500 gigabyte hard drive")
// convert Windows.Data.Json to LINQ to JSON
JObject o = JObject.FromObject(jsonObject);
// convert LINQ to JSON to Windows.Data.Json
JArray a = (JArray)o["Drives"];
JsonArray jsonArray = a.ToObject<JsonArray>();

Json.NET 4.5 Release 8 – Multidimensional Array Support, Unicode Improvements

Multidimensional Array Support

Json.NET now supports serializing and deserializing multidimensional arrays. There isn't anything you need to do, if one of your types has a multidimensional array property It Just Works™.

string[,] famousCouples = new string[,]
    { "Adam", "Eve" },
    { "Bonnie", "Clyde" },
    { "Donald", "Daisy" },
    { "Han", "Leia" }
string json = JsonConvert.SerializeObject(famousCouples, Formatting.Indented);
// [
//   ["Adam", "Eve"],
//   ["Bonnie", "Clyde"],
//   ["Donald", "Daisy"],
//   ["Han", "Leia"]
// ]
string[,] deserialized = JsonConvert.DeserializeObject<string[,]>(json);
Console.WriteLine(deserialized[3, 0] + ", " + deserialized[3, 1]);
// Han, Leia

Unicode Performance Improvements

Prior versions of Json.NET allocated a new array and string object to the heap for every Unicode character; a potentially expensive situation if your application is writing a lot of Unicode characters.

This release improves Unicode serialization so that Json.NET will only allocate a single array for all Unicode text and then writes the text directly to the underlying output stream. These changes improve Json.NET performance of Unicode intensive objects by about 20% and significantly reduces the time spent doing garbage collection.


Here is a complete list of what has changed since Json.NET 4.5 Release 7.

  • New feature - Serialize and deserialize multidimensional arrays
  • New feature - Members on dynamic objects with JsonProperty/DataMember will now be included in serialized JSON
  • New feature - LINQ to JSON load methods will read past preceding comments when loading JSON
  • New feature - Improved error handling to return incomplete values upon reaching the end of JSON content
  • Change - Improved performance and memory usage when serializing Unicode characters
  • Change - The serializer now creates objects using GetUninitializedObject when deserializing a Serializable type
  • Fix - Added SecurityTransparent attribute to WinRT build
  • Fix - Fixed infinite loop error caused by error handling upon reaching the end of JSON content


Json.NET CodePlex Project

Json.NET 4.5 Release 8 Download – Json.NET source code and assemblies

Json.NET 4.5 Release 5 – JsonProperty enhancements

JsonProperty enhancements

JsonPropertyAttribute now has options on it to customize a property’s collection items. When ItemConverter, ItemIsReference, ItemTypeNameHandling or ItemReferenceLoopHandling is set on JsonProperty and the property’s type is a collection then those settings will be applied to every collection item.

public class Event
  public string EventName { get; set; }
  public string Venue { get; set; }
  [JsonProperty(ItemConverterType = typeof(JavaScriptDateTimeConverter))]
  public IList<DateTime> Performances { get; set; }


Event e = new Event
    EventName = "Blackadder III",
    Venue = "Gryphon Theatre",
    Performances = new List<DateTime>
        DateTime.Parse("8 Tue May 2012, 6:30pm"),
        DateTime.Parse("9 Wed May 2012, 6:30pm"),
        DateTime.Parse("10 Thu May 2012, 8:00pm")
string json = JsonConvert.SerializeObject(e, Formatting.Indented);
//  "EventName": "Blackadder III",
//  "Venue": "Gryphon Theatre",
//  "Performances": [
//    new Date(1336458600000),
//    new Date(1336545000000),
//    new Date(1336636800000)
//  ]


Here is a complete list of what has changed since Json.NET 4.5 Release 4.

  • New feature - Added ItemIsReference, ItemReferenceLoopHandling, ItemTypeNameHandling, ItemConverterType to JsonPropertyAttribute
  • New feature - Added ItemRequired to JsonObjectAttribute
  • New feature - Added Path to JsonWriterException
  • Change - Improved deserializer call stack memory usage
  • Change - Moved the PDB files out of the NuGet package into a symbols package
  • Fix - Fixed infinite loop from an input error when reading an array and error handling is enabled
  • Fix - Fixed a base object error not being handled when deserializing


Json.NET CodePlex Project

Json.NET 4.5 Release 5 Download – Json.NET source code, documentation and binaries

Json.NET 4.5 Release 4 – Portable Class Library Build

They took my dressing room, my parking space, even my writer, so I don't have a funny third item.Portable Class Library Build

Json.NET now has a Portable Class Library build that can be found in the /Bin/Portable directory from the zip download on CodePlex. The portable build targets the absolute basics (.NET 4.0, SL4, WP7, Metro) and so hopefully should run on just about everything.

Improved Collection Serialization

JsonArrayAttribute and JsonDictionaryAttribute now have properties to customize the serialization of collection items. ItemConverter, ItemTypeNameHandling, ItemReferenceLoopHandling and ItemIsReference will apply to all the items of that list/dictionary when serializing and deserializing.


  • New feature – Added Portable Class Library build
  • New feature - Added support for customizing the JsonConverter, type name handling and reference handling of collection items
  • New feature - Added Path to JsonReaderException/JsonSerializationException messages
  • New feature - Added DateParseHandling to JsonReader
  • New feature - Added JsonContainerContract
  • New feature - Added JsonDictionaryAttribute
  • Change – Instances of Exception have been changed to be a more specific exception
  • Fix – Fixed Windows Application Certification tool error by removing AllowPartiallyTrustedCallersAttribute
  • Fix - Fixed JsonWriters not using DateTimeZoneHandling


Json.NET CodePlex Project

Json.NET 4.5 Release 4 Download – Json.NET source code, documentation and binaries