Benchmark: data-attribute vs className

HTML Preparation code:

<div id="foo"></div>
<style>
  #foo {
    height: 50px;
    box-shadow: 0 0 0 red;
  }
  #foo.bar {
    box-shadow: 0 0 0 3px red;
  }
  #foo[data-baz] {
  }
</style>

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.className = "bar"; }
data-attribute
var element = document.getElementById("foo"); var boxShadow = element.style.boxShadow.split(' '); boxShadow[3] = '3px' boxShadow = boxShadow.join(' '); var i = 1000; while (i--) { element.setAttribute('baz', "1"); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
className
data-attribute

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36

Browser/OS: Chrome 90 on Windows

View result in a separate tab

Test name	Executions per second
className	4678.7 Ops/sec
data-attribute	2815.7 Ops/sec

data-attribute vs className (version: 7)

Comparing performance of: className vs data-attribute

Created: 3 years ago by: Registered User

Jump to the latest result

className

data-attribute

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A