getElementsByClassName VS querySelectorAll

JavaScript performance comparison

Revision 11 of this test case created

Preparation code

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

Preparation code output

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

Testing in unknown unknown
Test Ops/sec
getElementsByClassName
nodes = document.getElementsByClassName('classname');
ilength = nodes.length;
arr = [];
        for (i=0; i < ilength; i++ ){
            arr.push(nodes[i]);
        }
pending…
querySelectorAll
nodes = document.querySelectorAll('li .classname');
ilength = nodes.length;
arr = [];
        for (i=0; i < ilength; i++ ){
            arr.push(nodes[i]);
        }
pending…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

0 comments

Add a comment