getElementById vs. getElementsByClassName vs. querySelector vs. jQuery vs xpath

JavaScript performance comparison

Revision 145 of this test case created by ZAlexz

Preparation code

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js">
</script>
<p id="bar" class="my-bar">
  Bar
</p>
<div id="coo" class="my-foo">
  <div id="car" class="my-bar">
    <div id="caz" class="my-bar">
<div id="hoo" class="my-boo">
  <div id="har" class="my-bar">
    <div id="haz" class="my-bar">
<div id="yoo" class="my-boo">
  <div id="yar" class="my-bar">
    <div id="yaz" class="my-bar">
<div id="zoo" class="my-boo">
  <div id="zar" class="my-bar">
    <div id="zaz" class="my-bar">

      <span id="baz" class="my-baz">Baz</span>

    </div>
  </div>
</div>
    </div>
  </div>
</div>
    </div>
  </div>
</div>
    </div>
  </div>
</div>
      
<script>
Benchmark.prototype.setup = function() {
  function q(id){ return new Elem(document.getElementById(id));
  }
  
  var haz = document.getElementById('zaz');
  
  function Elem(el){ this._el = el; }
  Elem.prototype.append = function(){ this._el.appendChild(el); return this; }
  
  function qq(_class){ return document.getElementsByClassName(_class); }
  function qqTag(tag){ return document.getElementsByTagName(tag); }

};
</script>

Preparation code output

<p id="bar" class="my-bar"> Bar </p> <div id="coo" class="my-foo"> <div id="car" class="my-bar"> <div id="caz" class="my-bar"> <div id="hoo" class="my-boo"> <div id="har" class="my-bar"> <div id="haz" class="my-bar"> <div id="yoo" class="my-boo"> <div id="yar" class="my-bar"> <div id="yaz" class="my-bar"> <div id="zoo" class="my-boo"> <div id="zar" class="my-bar"> <div id="zaz" class="my-bar"> <span id="baz" class="my-baz">Baz</span> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div>

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
getElementById
var baz = document.getElementById("baz");
pending…
q(id)
var bar = q('baz');
pending…
el.getElementsByClassName
var baz = haz.getElementsByClassName('my-baz');
pending…
qq(class)
var baz = qq('my-baz');
pending…

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Revisions

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