Run results for: getElementById vs querySelector

Run details:

User agent: Mozilla/5.0 (Linux; Android 9; Mi A1 Build/PKQ1.180917.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.120 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/324.0.0.48.120;]

Browser: Chrome Mobile 91

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
getElementById	492305.7 Ops/sec
querySelector	303975.9 Ops/sec

HTML Preparation code:

<div id="testElement"></div>

Tests:

getElementById
var el = document.getElementById('testElement'); var className = el.className;
querySelector
var el = document.querySelector('#testElement'); var className = el.className;