GZip a string in c#

gzipexample.cs

MemoryStream mem = new MemoryStream();
using (GZipStream gz = new GZipStream(mem, CompressionLevel.Optimal, true))
{
    var b = Encoding.UTF8.GetBytes(json);
    gz.Write(b, 0, b.Length);
    gz.Flush();
}

var data = mem.ToArray();