Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Linux; Android 7.1.1; XT1635-02 Build/NPNS26.118-22-2-12) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.137 Mobile Safari/537.36

Browser: Chrome Mobile 64

Operating system: Android 7.1.1

Device Platform: XT1635-02

Date tested: 2025 years ago

Test name	Executions per second
className	404.0 Ops/sec
setAttribute	339.9 Ops/sec
classList	294.6 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"); }