using System;

public class Program

{

    public static void Main()

    {

        Guid newGuid = Guid.NewGuid();

        Console.WriteLine(string.Format("new guid {0} length:{1}",newGuid.ToString(),newGuid.ToString().Length));

        string encoded = EncodeGuid(newGuid);

        Console.WriteLine(string.Format("encoded {0} length:{1}",encoded, encoded.Length));

        Guid decoded = DecodeGuid(encoded);

        Console.WriteLine(string.Format("decoded {0} length:{1}",decoded, decoded.ToString().Length));

    }

    static string EncodeGuid(Guid guid)

    {

        Span<byte> bytes = stackalloc byte[16];

        guid.TryWriteBytes(bytes);

        return Microsoft.AspNetCore.WebUtilities.WebEncoders.Base64UrlEncode(bytes);

    }

​

    static Guid DecodeGuid(string guid)

    {

        return new Guid(Microsoft.AspNetCore.WebUtilities.WebEncoders.Base64UrlDecode(guid));

    }

}