Run results for: querySelectorAll vs getElementsByTagName

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.24 Safari/537.36 Edg/83.0.478.18

Browser: Chrome 83

Operating system: Mac OS X 10.15.4

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
querySelectorAll	5471.6 Ops/sec
getElementsByTagName	4323.6 Ops/sec

HTML Preparation code:

<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>

Tests:

querySelectorAll
const allDivs = document.querySelectorAll('div'); allDivs.forEach(function (div) { console.log(div); });
getElementsByTagName
const allDivs = document.getElementsByTagName('div'); const arrayAllDivs = Array.from(allDivs); arrayAllDivs.forEach(function (div) { console.log(div); });