Run results for: getElementsByClass vs. querySelector

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Browser: Chrome 90

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
queryselector	4989222.0 Ops/sec
class by name	4411250.0 Ops/sec

HTML Preparation code:

<div class="wrapper">
  <div class="item"></div>
    <div class="item"></div>
    <div class="item"></div>
    <div class="item"></div>
</div>
<script src='https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js'></script>

Tests:

queryselector
document.querySelector(".item");
class by name
document.getElementsByClassName("test");

Run results for: getElementsByClass vs. querySelector

queryselector

class by name