XMLHttpRequest.js example

XMLHttpRequest.js

var getJSON = function(url, callback) {

  var xhr = new XMLHttpRequest();
  xhr.open('GET', url, true);
  xhr.responseType = 'json'; // or html (returns as accessible document!) or text (default):
                             // https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/responseType

  xhr.onload = function() {

    var status = xhr.status;

    if (status == 200) {
      callback(null, xhr.response);
    } else {
      callback(status);
    }
  };

  xhr.send();
};

getJSON(YOUR_URL, function(err, data) {
  if (err != null) {
    console.error(err);
  } else {
    console.log(data); // read text, parse javascript object or access DOM via document.<dowhatever>
  }
});