Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36 OPR/57.0.3098.110

Browser: Opera 57

Operating system: Mac OS X 10.14.2

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
className	473.5 Ops/sec
setAttribute	398.4 Ops/sec
classList	418.9 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"); }