Hello! I've mentioned that response content always encoded with Encoding.Default. as I can see the problem is in RestSharp/src/RestSharp/Response/ResponseHandling.cs static class ResponseHandling { public static string GetResponseString(this HttpResponseMessage response, byte[] bytes) { var encodingString = response.Content.Headers.ContentEncoding.FirstOrDefault(); ContentEncoding has'no info about charset https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding may be it is better to get charset info from response.Content.Headers.ContentType.CharSet?