Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:122.0) Gecko/20100101 Firefox/122.0

Browser: Firefox 122

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

className

42K/s

setAttribute

25K/s

classList

12K/s

View exact numbers

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"); }