Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Linux; Android 4.4.2; HM NOTE 1LTE Build/KVT49L) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.83 Mobile Safari/537.36

Browser: Chrome Mobile 58

Operating system: Android 4.4.2

Device Platform: HM NOTE 1LTE

Date tested: 7 years ago

Test name	Executions per second
className	138.8 Ops/sec
setAttribute	99.1 Ops/sec
classList	302.8 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"); }