Run results for: className vs classList with existing classes

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:123.0) Gecko/20100101 Firefox/123.0

Browser: Firefox 123

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

className

3K/s

classList

2K/s

View exact numbers

Test name	Executions per second
✓ className	3,311 Ops/sec
classList	1,970 Ops/sec

HTML Preparation code:

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

Tests:

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