Run results for: querySelectorAll vs getElementsByTagName iteration

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 13_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 LightSpeed [FBAN/MessengerLiteForiOS;FBAV/291.2.0.30.111;FBBV/257403963;FBDV/iPhone11,6;FBMD/iPhone;FBSN/iOS;FBSV/13.4.1;FBSS/3;FBCR/;FBID/phone;FBLC/vi;FBOP/0]

Browser: Mobile Safari 13

Operating system: iOS 13.4.1

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
querySelectorAll	1431119.4 Ops/sec
getElementsByTagName	1212607.1 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) {});