Run results for: getElementById vs QuerySelector nested element

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36

Browser: Chrome 100

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
getElementById + firstElementChild	9071615.0 Ops/sec
querySelector	5456384.0 Ops/sec

HTML Preparation code:


<div id="testElmt">
  <p>paragraph</p>
</div>

Tests:

getElementById + firstElementChild
const par = document.getElementById("testElmt").firstElementChild;
querySelector
const par = document.querySelector("#testElmt p");