Duolingo vocab parser for Words page

vocab_parser.js

/* Pulling out vocab from Duolingo's Words page */

var raw,
    cleaned,
    filtered,
    xhr = new XMLHttpRequest;

var parser = function(data) {
  raw = JSON.parse(data);
  cleaned = raw.vocab_overview.filter(function(word) {
    if (word.strength_bars < 3) {
      return true;
    }
  });
  filtered = cleaned.map(function(d) {
    return d.normalized_string;
  });
  console.dir(filtered);
}

xhr.open('GET', '/vocabulary/overview?_=1410893871725', true);
xhr.responseType = 'text';
xhr.onload = function() {
  if (this.status == 200) {
    parser(this.response)
  }
}
xhr.send();