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

Run details:

User agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0

Browser: Firefox 115

Operating system: Windows 8.1

Device Platform: Desktop

Date tested: one year ago

classList

1.1M/s

className

17K/s

View exact numbers

Test name	Executions per second
✓ classList	1,079,737 Ops/sec
className	16,958 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.includes("test")) {} }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.contains("test"); }