Run results for: querySelectorAll vs getElementsByTagName iteration

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:123.0) Gecko/20100101 Firefox/123.0

Browser: Firefox 123

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

querySelectorAll

1.3M/s

getElementsByTagName

1.2M/s

View exact numbers

Test name	Executions per second
✓ querySelectorAll	1,321,857 Ops/sec
getElementsByTagName	1,231,234 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) {});
getElementsByTagName
const allDivs = document.getElementsByTagName('div'); const arrayAllDivs = Array.from(allDivs); arrayAllDivs.forEach(function (div) {});