Run results for: className vs data attr querySelectorAll vs getElementsByClassName

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_5_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.5.1

Device Platform: Mobile

Date tested: 3 months ago

Test name	Executions per second
querySelectorAll data attr	1895605.0 Ops/sec
querySelectorAll data attr plus node name	1394072.0 Ops/sec
querySelectorAll class name	5712417.0 Ops/sec
querySelectorAll class name plus node name	1532051.0 Ops/sec
querySelectorAll node name plus class name plus data attr	1371442.0 Ops/sec
getElementsByClassName	8097328.0 Ops/sec

HTML Preparation code:

<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>
<div class="component-1" data-js="component-1"></div>

<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>
<div class="component-2" data-js="component-2"></div>

Tests:

querySelectorAll data attr
var result = document.querySelectorAll("[data-js='component-1']");
querySelectorAll data attr plus node name
var result = document.querySelectorAll("div[data-js='component-1']");
querySelectorAll class name
var result = document.querySelectorAll('.component-1')
querySelectorAll class name plus node name
var result = document.querySelectorAll('div.component-1');
querySelectorAll node name plus class name plus data attr
var result = document.querySelectorAll("div.component-1[data-js='component-1']");
getElementsByClassName
document.getElementsByClassName('component-1')

Run results for: className vs data attr querySelectorAll vs getElementsByClassName

This benchmark compares the performance of different methods for selecting elements in JavaScript: querySelectorAll and getElementsByClassName.

querySelectorAll data attr

querySelectorAll data attr plus node name

querySelectorAll class name

querySelectorAll class name plus node name

querySelectorAll node name plus class name plus data attr

getElementsByClassName