Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.0) Gecko/20100101 Firefox/137.0

Browser: Firefox 137

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

className

39K/s

setAttribute

24K/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"); }