Run results for: className vs. setAttribute vs. classList

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36

Browser: Chrome 54

Operating system: Mac OS X 10.11.6

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
className	3385.7 Ops/sec
classList	925.2 Ops/sec

HTML Preparation code:

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

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.className = "bar bar1 bar2 bar3 bar4"; }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); element.classList.add("bar1"); element.classList.add("bar2"); element.classList.add("bar3"); element.classList.add("bar4"); }