Run results for: className vs. setAttribute data attribute vs. classList

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.4

Device Platform: Mobile

Date tested: 2 years ago

Benchmark engine: Benchmark.js

className

69K/s

setAttribute

31K/s

classList

26K/s

View exact numbers

HTML Preparation code:

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

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.className = "is-active"; }
setAttribute
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.setAttribute("data-state", "active"); }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("is-active"); }