Because of closing tags, XML is approximately twice as noisy as JSON encoding. If response sizes and the network traffic they entail are a concern, JSON is wort

Because of closing tags, XML is approximately twice as noisy as JSON encoding. If response sizes and the network traffic they entail are a concern, JSON is worth considering. If response sizes + validation are necessary, something like Protocol Buffers or Thrift may also fit, as they are widely supported as well.