Run results for: getElementById vs querySelector ID vs getElementsByClassName vs querySelectorAll

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; SAMSUNG SM-G965F) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/13.2 Chrome/83.0.4103.106 Mobile Safari/537.36

Browser: Chrome Mobile 83

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
getElementById	1259908.0 Ops/sec
querySelector	643985.2 Ops/sec
getElementsByClassName	966184.5 Ops/sec
querySelectorAll	403723.6 Ops/sec
querySelector class	986392.8 Ops/sec

HTML Preparation code:

<div id="test_element_id" class="test_element_class"></div>

Tests:

getElementById
var el = document.getElementById('test_element_id'); var className = el.className;
querySelector
var el = document.querySelector('#test_element_id'); var className = el.className;
getElementsByClassName
var el = document.getElementsByClassName('test_element_class')[0]; var className = el.className;
querySelectorAll
var el = document.querySelectorAll('.test_element_class')[0]; var className = el.className;
querySelector class
var el = document.querySelector('.test_element_class'); var className = el.className;

Run results for: getElementById vs querySelector ID vs getElementsByClassName vs querySelectorAll

getElementById

querySelector

getElementsByClassName

querySelectorAll

querySelector class