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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser: Chrome 120

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

classList.add

18K/s

setAttribute(...)

9/s

classList.value

4/s

className

2/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"; }