C# Online Compiler | .NET Fiddle

using System; using System.Text.RegularExpressions; using System.Net;  
using System.Web; using System.Text;
					
public static class Program
{
	//Tue 20-Aug-19 6:53pm Markus - http://metadataconsulting.blogspot.com/2019/08/Remove-all-ANSI-Control-Characters-fast-in-C-Sharp.html
	public static string RemoveUnicodeControlChars(this string s) {
  
  		StringBuilder sb = new StringBuilder(s.Length);
  		for (int i = 0; i < s.Length; i++) 
   		if ( !Char.IsControl(s[i]) )
    		sb.Append(s[i]);
   
  		return sb.ToString(); 
 	}
	
	public static string URLExpander(this string URL) {
	
		    //removal ASCII and UNICODE control characters, if they exist
            //string urlText = Regex.Replace(URL, @"[\u0000-\u0008|\u000B-\u000C|\u000E-\u001F|\u0080-\u009F]", "");
		    string urlText = URL.RemoveUnicodeControlChars(); 
		
            if (string.IsNullOrWhiteSpace(urlText))
                return string.Empty; 

            Uri uriResult;

		    //validate URL
            bool result = Uri.TryCreate(urlText, UriKind.Absolute, out uriResult)
            && (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps
				|| uriResult.Scheme == Uri.UriSchemeFtp || uriResult.Scheme == Uri.UriSchemeFile
			    ); //or other schemes

            if (!result)
          		return string.Empty;

            //https://docs.microsoft.com/en-us/dotnet/api/system.net.httpwebrequest?view=netframework-4.8
		    HttpWebRequest req = null; 
            HttpWebResponse response; 
		
            try
            {
            	req = (HttpWebRequest)WebRequest.Create(uriResult); 
                req.Method = "HEAD";
                req.AllowAutoRedirect = false;
                result = true; 
            }
            catch (NotSupportedException)
            {
                result = false; //add your exception handling here
                
            }
            catch (ArgumentNullException)
            {
                result = false; //add your exception handling here

            }
            catch (System.Security.SecurityException)
            {
                result = false; //add your exception handling here

            }
            catch (UriFormatException)
            {
                result = false; //add your exception handling here
			}

            if (!result)
            	return string.Empty; 
            
			string redirectedURL = ""; 
            try
            {
                response =  (HttpWebResponse)req.GetResponse();
				
				//https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
				//304 Not Modified - Redirection to a previously cached result -> may not be a URL redirection
				//restrictive
				if ((int)response.StatusCode >= 300 && ((int)response.StatusCode < 400))
				{
					redirectedURL = response.Headers[HttpResponseHeader.Location]; //or url = response.Headers["Location"];
				}
				else if ((int)response.StatusCode < 300 || (int)response.StatusCode >= 400) //okay
				{
					redirectedURL = uriResult.ToString(); //set as validated URL
				}								

				result = true; 
            }       
            catch (System.Net.WebException)
            {
                result = false; 
            }
            catch (System.Net.ProtocolViolationException)
            {
                result = false; 
            }
            catch (InvalidOperationException)
            {
                result = false;                 
            }
            catch (NotSupportedException)
            {
                result = false; 
            }
            
            if (!result)
            	return string.Empty;
		
			try {
            	
				redirectedURL = HttpUtility.UrlDecode(redirectedURL);
			}
			catch 
            {
                return string.Empty; 
            }
		
		    return redirectedURL; 
		
	}
	
	public static void Main()
	{
		string testURL = "http://bit.ly/AzureAITranslation"; 
		string testURL2 = "https://metadataconsulting.blogspot.com"; 
	
			//sanity check - no redirect especially for status code 304 (which is cached URL)
		string expandoURL = testURL.URLExpander(); 
		
		if (testURL == expandoURL)
			Console.WriteLine("source URL same as output URL");
		else if (testURL + "/" == expandoURL) 
			Console.WriteLine("source URL same as output URL");
        else
			Console.WriteLine("source URL expands to new URL");
	
			
		Console.WriteLine(testURL + "\nexpands to\n" + testURL.URLExpander());
		Console.WriteLine(); 
		
        expandoURL = testURL2.URLExpander(); 
		if (testURL2 == expandoURL)
			Console.WriteLine("source URL same as output URL");
		else if (testURL2 + "/" == expandoURL) 
			Console.WriteLine("source URL same as output URL");
        else
			Console.WriteLine("source URL expands to new URL");
		Console.WriteLine(testURL2 + "\nexpands to\n" + testURL2.URLExpander());


	}
}

 
using System; using System.Text.RegularExpressions; using System.Net;  
using System.Web; using System.Text;
                    
public static class Program
{
    //Tue 20-Aug-19 6:53pm Markus - http://metadataconsulting.blogspot.com/2019/08/Remove-all-ANSI-Control-Characters-fast-in-C-Sharp.html
    public static string RemoveUnicodeControlChars(this string s) {
  
        StringBuilder sb = new StringBuilder(s.Length);
        for (int i = 0; i < s.Length; i++) 
        if ( !Char.IsControl(s[i]) )
            sb.Append(s[i]);
   
        return sb.ToString(); 
    }
    
    public static string URLExpander(this string URL) {
    
            //removal ASCII and UNICODE control characters, if they exist
            //string urlText = Regex.Replace(URL, @"[\u0000-\u0008|\u000B-\u000C|\u000E-\u001F|\u0080-\u009F]", "");
            string urlText = URL.RemoveUnicodeControlChars(); 
        
            if (string.IsNullOrWhiteSpace(urlText))
                return string.Empty; 

Cached Result

source URL expands to new URL
http://bit.ly/AzureAITranslation
expands to
https://metadataconsulting.blogspot.com/2018/12/How-to-Translate-any-Foreign-Language-Document-to-English-Successfully-using-AI.html

source URL same as output URL
https://metadataconsulting.blogspot.com
expands to
https://metadataconsulting.blogspot.com/