Make HEAD request to get content info as JSON

getContentInfo.cs

//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Net.Http;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            HttpClient client = new HttpClient();

             var response = client.GetAsync("http://dr.dk").Result;

            if (response.IsSuccessStatusCode)
            {
                // by calling .Result you are performing a synchronous call
                var responseContent = response.Content; 

                // by calling .Result you are synchronously reading the result
                string responseString = responseContent.ReadAsStringAsync().Result;
                
                var headers = response.Content.Headers;
                
                string json = "{\"length\":"+headers.ContentLength+",\"type\":"+headers.ContentLength+"}";

                Console.WriteLine(json);
            }
        }
    }
}

Try it here: http://rextester.com/YBZ73344