Can JavaScriptSerializer exclude properties with null/default values?

FYI, if you’d like to go with the easier solution, here’s what I used to accomplish this using a JavaScriptConverter implementation with the JavaScriptSerializer:

private class NullPropertiesConverter: JavaScriptConverter {
 public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer) {
  throw new NotImplementedException();

 public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer) {
  var jsonExample = new Dictionary<string, object >();
  foreach(var prop in obj.GetType().GetProperties()) {
   //check if decorated with ScriptIgnore attribute
   bool ignoreProp = prop.IsDefined(typeof(ScriptIgnoreAttribute), true);

   var value = prop.GetValue(obj, BindingFlags.Public, null, null, null);
   if (value != null && !ignoreProp)
    jsonExample.Add(prop.Name, value);

  return jsonExample;

 public override IEnumerable<Type> SupportedTypes {
  get {
   return GetType().Assembly.GetTypes();

and then to use it:

var serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new JavaScriptConverter[] {
  new NullPropertiesConverter()
return serializer.Serialize(someObjectToSerialize);

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