Run results for: className vs classList with existing classes

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser: Chrome 122

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

className

18K/s

classList

4K/s

View exact numbers

Test name	Executions per second
✓ className	18,234 Ops/sec
classList	3,933 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"); }