Run results for: document.body.getElementsByClassName vs document.getElementsByClassName +

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36

Browser: Chrome 109

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

getElementsByClassName

8.8M/s

body.getElementsByClassName

7.2M/s

View exact numbers

Test name	Executions per second
✓ getElementsByClassName	8,804,723 Ops/sec
body.getElementsByClassName	7,221,052 Ops/sec

HTML Preparation code:

<!DOCTYPE html>
<html lang="ru">
<head>
</head>
<body>
  <div class="aap">AAP</div>
</body>
</html>

Tests:

getElementsByClassName
const classElm = document.getElementsByClassName('aap')[0];
body.getElementsByClassName
const classElm = document.body.getElementsByClassName('aap')[0];