Run results for: className.indexOf vs. classList.contains

Run details:

User agent: Mozilla/5.0 (X11; CrOS x86_64 13310.41.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.59 Safari/537.36

Browser: Chrome 85

Operating system: Chrome OS 13310.41.0

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
className	37807.8 Ops/sec
classList	8158.9 Ops/sec

HTML Preparation code:

<div id="foo" class="test"></div>

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { if (element.className.indexOf("test") !== -1) {} }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.contains("test"); }