Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/130.0.6723.90 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 130

Operating system: iOS 18.1

Device Platform: Mobile

Date tested: one year ago

className

9.7M/s

setAttribute

7.8M/s

classList

7.4M/s

View exact numbers

Test name	Executions per second
✓ className	9,736,651 Ops/sec
setAttribute	7,780,848 Ops/sec
classList	7,382,934 Ops/sec

HTML Preparation code:

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

Script Preparation code:

var element = document.getElementById("foo");

Tests:

className
element.className = "bar";
setAttribute
element.setAttribute("class", "bar");
classList
element.classList.add("bar");