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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser: Chrome 133

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

getElementsByClassName

12.9M/s

querySelector.body

10.8M/s

getElementsByClassName BODY

10.7M/s

querySelector

10.7M/s

View exact numbers

Test name	Executions per second
✓ getElementsByClassName	12,894,857 Ops/sec
querySelector.body	10,805,101 Ops/sec
getElementsByClassName BODY	10,749,283 Ops/sec
querySelector	10,678,444 Ops/sec

HTML Preparation code:

<div class="testElement"></div>

Tests:

querySelector
var el = document.querySelector('.testElement');
querySelector.body
var el = document.body.querySelector('.testElement');
getElementsByClassName
var el = document.getElementsByClassName('testElement');
getElementsByClassName BODY
var el = document.body.getElementsByClassName('testElement');