Run results for: getElementById vs querySelector vs querySelector for some other attribute vs querySelectorAll for some other attribute

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_0_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.67 Safari/537.36

Browser: Chrome 87

Operating system: Mac OS X 11.0.1

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
getElementById	5414969.0 Ops/sec
querySelector	3084657.8 Ops/sec
querySelector for some other attribute	2136420.2 Ops/sec
querySelectorAll for some other attribute	1000710.3 Ops/sec

HTML Preparation code:

<div id="testElement" at="testElement"></div>

Tests:

getElementById
var el = document.getElementById('testElement'); var className = el.className;
querySelector
var el = document.querySelector('#testElement'); var className = el.className;
querySelector for some other attribute
var el = document.querySelector('[at="testElement"]'); var className = el.className;
querySelectorAll for some other attribute
var el = document.querySelectorAll('[at="testElement"]'); var className = el[0].className;