Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; COL-AL10 Build/HUAWEICOL-AL10; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.186 Mobile Safari/537.36 Lark/3.23.0-beta1 LarkLocale/zh_CN TTWebView/0621111014040

Browser: Chrome Mobile 74

Operating system: Android

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
className	2288.6 Ops/sec
setAttribute	1711.3 Ops/sec
classList	1295.1 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"); }