Run results for: className vs classList add,remove

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:151.0) Gecko/20100101 Firefox/151.0

Browser: Firefox 151

Operating system: Ubuntu

Device Platform: Desktop

Date tested: one month ago

className

1K/s

classList

936/s

View exact numbers

Test name	Executions per second
✓ className	1,424 Ops/sec
classList	936 Ops/sec

HTML Preparation code:

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

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { if (i % 2 === 0) { element.className += "buzz"; } else { element.className = "fizz"; } }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { if (i % 2 === 0) { element.classList.add("buzz"); } else { element.classList.remove("buzz"); } }