Run results for: querySelectorAll vs getElementsByTagName iteration

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_0_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/132.1 Mobile/15E148 Safari/605.1.15

Browser: Mobile Safari 18

Operating system: iOS 18.0.1

Device Platform: Mobile

Date tested: one year ago

querySelectorAll

2.0M/s

getElementsByTagName

1.6M/s

View exact numbers

Test name	Executions per second
✓ querySelectorAll	2,043,730 Ops/sec
getElementsByTagName	1,566,626 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) {});