Lowercase Json result in ASP.NET MVC 5

The best solution I have for this is to override the default Json method to use Newtonsoft.Json and set it to use camelcase by default.

First thing is you need to make a base controller if you don't have one already and make your controllers inherit that.

public class BaseController : Controller {
}

Next you create a JsonResult class that will use Newtonsoft.Json :

public class JsonCamelcaseResult : JsonResult
{
    private static readonly JsonSerializerSettings _settings = new JsonSerializerSettings
    {
        ContractResolver = new CamelCasePropertyNamesContractResolver(),
        Converters = new List<JsonConverter> { new StringEnumConverter() }
    };

    public override void ExecuteResult(ControllerContext context)
    {
        HttpResponseBase response = context.HttpContext.Response;
        response.ContentType = !String.IsNullOrEmpty(this.ContentType) ? this.ContentType : "application/json";
        response.ContentEncoding = this.ContentEncoding ?? response.ContentEncoding;

        if (this.Data == null)
            return;

        response.Write(JsonConvert.SerializeObject(this.Data, _settings));
    }
}

Then in your BaseController you override the Json method :

protected new JsonResult Json(object data)
{
    return new JsonCamelcaseResult
    {
        Data = data,
        JsonRequestBehavior = JsonRequestBehavior.AllowGet
    };
}

So in the end in your original action returning JSON you just keep it the same and the properties will be camelcased (propertyName) instead of pascalcased (PropertyName) :

[HttpGet]
public JsonResult Method()
{
    var vms = new List<MyViewModel>()
    {
         new MyViewModel()
         {
              Name = "John Smith",
         }
    };

    return Json(new { results = vms });
}