Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Linux; Android 6.0.1; SAMSUNG SM-N910F Build/MMB29M) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/6.4 Chrome/56.0.2924.87 Mobile Safari/537.36

Browser: Chrome Mobile 56

Operating system: Android 6.0.1

Device Platform: Samsung SM-N910F

Date tested: 2025 years ago

Test name	Executions per second
className	252.6 Ops/sec
setAttribute	221.2 Ops/sec
classList	651.5 Ops/sec

HTML Preparation code:

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

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.className = "bar"; }
setAttribute
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.setAttribute("class", "bar"); }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); }