Fully async ga

fully_async_ga.js

if (!DDAsyncLoad) {
  function DDAsyncLoad(cb) {
    if (window.attachEvent) {
      window.attachEvent('onload', cb);
    } else {
      window.addEventListener('load', cb, false);
    }
  }
}

DDAsyncLoad && DDAsyncLoad(function () {
  setTimeout(function () {
    (function (i, s, o, g, r, a, m) {
    i['GoogleAnalyticsObject'] = r; i[r] = i[r] || function () {
      (i[r].q = i[r].q || []).push(arguments)
    }, i[r].l = 1 * new Date(); a = s.createElement(o),
      m = s.getElementsByTagName(o)[0]; a.async = 1; a.src = g; m.parentNode.insertBefore(a, m)
    })(window, document, 'script', 'https://www.google-analytics.com/analytics.js', 'ga');

    ga('create', 'UA-XXX-1', 'auto');
    ga('send', 'pageview');
  }, 100);
});