Run results for: Selectors

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:79.0) Gecko/20100101 Firefox/79.0

Browser: Firefox 79

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
querySelector (id)	1800672.6 Ops/sec
getElementById	3194781.0 Ops/sec

HTML Preparation code:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js">
</script>
<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 id="last">
      <a href="#" name="name" class="classname">item 10</a>
    </li>
  </ul>
</div>

Script Preparation code:

var node;

Tests:

querySelector (id)
node = document.querySelector('#last');
getElementById
node = document.getElementById('last');

Comparing various JS selector speeds

querySelector (id)

getElementById