Run results for: Testing getElementById vs getElementsByClassName vs querySelector vs querySelectorAll

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_8 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/93.0.4577.39 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 93

Operating system: iOS 14.8

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
getElementById	6243466.0 Ops/sec
getElementsByClassName	6032149.0 Ops/sec
querySelector	4718493.0 Ops/sec
querySelectorAll	2970453.0 Ops/sec

HTML Preparation code:

<div class="test" id="testing"></div>

Tests:

getElementById
document.getElementById("testing")
getElementsByClassName
document.getElementsByClassName("test")
querySelector
document.querySelector(".test")
querySelectorAll
document.querySelectorAll(".test")