Run results for: className vs classList

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser: Chrome 141

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 6 months ago

Test name	Executions per second
className	3.1 Ops/sec
classList	4880.0 Ops/sec

HTML Preparation code:

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

Tests:

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