Run results for: setAttribute(...) vs. classList.add(...) vs classList.value vs className (multiple classes, no override)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:120.0) Gecko/20100101 Firefox/120.0

Browser: Firefox 120

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

classList.add

19K/s

setAttribute(...)

8/s

classList.value

7/s

className

3/s

View exact numbers

HTML Preparation code:

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

Tests:

setAttribute(...)
var element = document.getElementById("foo"); var i = 100; while (i--) { element.setAttribute("class", element.className + " bar baz qwe"); }
classList.add
var element = document.getElementById("foo"); var i = 100; while (i--) { element.classList.add("bar", "baz", "qwe"); }
classList.value
var element = document.getElementById("foo"); var i = 100; while (i--) { element.classList.value = element.className + " bar baz qwe"; }
className
var element = document.getElementById("foo"); var i = 100; while (i--) { element.className = element.className + " bar baz qwe"; }