Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Linux; U; Android 10; Infinix X655C Build/QP1A.190711.020; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/84.0.4147.125 Mobile Safari/537.36 OPR/52.1.2254.54298

Browser: Opera Mobile 52

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
className	747.3 Ops/sec
setAttribute	442.0 Ops/sec
classList	476.8 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"); }