Run results for: jQuery by class vs Document.getElementsByClassName

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4421.0 Safari/537.36 Edg/90.0.810.1

Browser: Chrome 90

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
jQuery	359093.7 Ops/sec
Vanilla JS	2384751.0 Ops/sec

HTML Preparation code:

<script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.1.0.min.js"></script>
<div id="testElement" class="testClass"></div>
<div id="testElement2" class="testClass"></div>
<div id="testElement3" class="notTestClass"></div>

Tests:

jQuery
var el = $(".testClass")[0]; var className = el.className;
Vanilla JS
var el = document.getElementsByClassName('testClass')[0]; var className = el.className;

Run results for: jQuery by class vs Document.getElementsByClassName

Comparing speed of getting element by id with jQuery vs Vanilla JS

jQuery

Vanilla JS