Benchmark: className vs. classList - changing

HTML Preparation code:

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

Tests:

className =
var element = document.getElementById('foo'); var i = 1000; while (i--) { // vs using className element.className = 'B'; }
classList
var element = document.getElementById('foo'); var i = 1000; while (i--) { // Using classList element.classList.remove('A'); element.classList.add('B'); }

Rendered benchmark preparation results:

Previous results

Test case name	Result
className =
classList

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36

Browser/OS: Chrome 145 on Mac OS X 10.15.7

className =

22K/s

classList

4K/s

View exact numbers

Test name	Executions per second
✓ className =	21,763 Ops/sec
classList	3,684 Ops/sec

className vs. classList - changing (version: 1)