Run results for: getElementsByClassName VS querySelectorAll (simple comparison)

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.2 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 15

Operating system: iOS 15.2.1

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
The method getElementsByClassName()	11608004.0 Ops/sec
The method querySelectorAll()	3622859.5 Ops/sec

HTML Preparation code:

<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>
<div class="example container"></div>

Tests:

The method getElementsByClassName()
document.getElementById("example container");
The method querySelectorAll()
document.querySelectorAll(".example.container");

Run results for: getElementsByClassName VS querySelectorAll (simple comparison)

A simple comparison of performance between these two methods. (Medium, @benlmsc)

The method getElementsByClassName()

The method querySelectorAll()