Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 YaBrowser/21.2.4.165 Yowser/2.5 Safari/537.36

Browser: Yandex Browser 21

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
className	3855.9 Ops/sec
setAttribute	2080.5 Ops/sec
classList	2552.0 Ops/sec

HTML Preparation code:

<div id="foo"></div>

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.className = "bar"; }
setAttribute
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.setAttribute("class", "bar"); }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); }