Encode public static string Base64Encode ( string plainText ) { var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText); return System.Convert.ToBase64String(plainTextBytes); } Decode public static string Base64Decode ( string base64EncodedData ) { var base64EncodedBytes = System.Convert.FromBase64String(base64EncodedData); return System.Text.Encoding.UTF8.GetString(base64EncodedBytes); }