getElementsByClassName VS querySelectorAll(id) vs querySelectorAll(class)

JavaScript performance comparison

Revision 131 of this test case created by

Preparation code

<div>
  <ul>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 1</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 2</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 3</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 4</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 5</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 6</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 7</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 8</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 9</a>
    </li>
    <li>
      <a href="#" id="foo" name="name" class="foo">item 10</a>
    </li>
  </ul>
</div>
<script>
  var nodes;
</script>
    

Preparation code output

<div> <ul> <li> <a href="#" id="foo" name="name" class="foo">item 1</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 2</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 3</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 4</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 5</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 6</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 7</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 8</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 9</a> </li> <li> <a href="#" id="foo" name="name" class="foo">item 10</a> </li> </ul> </div>

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
getElementsByClassName
nodes = document.getElementsByClassName('foo');
pending…
querySelectorAll (id)
nodes = document.querySelectorAll('#foo');
pending…
querySelectorAll (class)
nodes = document.querySelectorAll('.foo');
pending…

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Revisions

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