KitKat test for WebSocket

gistfile1.js

function hasWebSocket() {
  var m = navigator.userAgent.match(/Android ([0-9]+)\.([0-9]+)/i);

  if (m) {
    var x = parseInt(m[1], 10);
    var y = parseInt(m[2], 10);

    return window.WebSocket && (x > 4 || (x == 4 && y >= 4));
  }

  return false;
}