Run results for: querySelectorAll vs getElementsByTagName + (fixed/dynamic) length + for

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 145

Operating system: Android

Device Platform: Mobile

Date tested: 6 months ago

Benchmark engine: Benchmark.js

Test name	Executions per second
✓ getElementsByTagName + length + for	16,349,283 Ops/sec
getElementsByTagName + dynamic length + for	3,935,222 Ops/sec
querySelectorAll + length + for	2,448,059 Ops/sec
querySelectorAll + dynamic length + for	2,029,682 Ops/sec
querySelectorAll + forEach	588,260 Ops/sec
getElementsByTagName + Array.from + forEach	388,747 Ops/sec

Test name

Executions per second

✓ getElementsByTagName + length + for

16,349,283 Ops/sec

getElementsByTagName + dynamic length + for

3,935,222 Ops/sec

querySelectorAll + length + for

2,448,059 Ops/sec

querySelectorAll + dynamic length + for

2,029,682 Ops/sec

querySelectorAll + forEach

588,260 Ops/sec

getElementsByTagName + Array.from + forEach

388,747 Ops/sec

Tests:

querySelectorAll + forEach
const allDivs = document.querySelectorAll('div'); allDivs.forEach(function (div) {});
getElementsByTagName + Array.from + forEach
const allDivs = document.getElementsByTagName('div'); const arrayAllDivs = Array.from(allDivs); arrayAllDivs.forEach(function (div) {});
querySelectorAll + length + for
const allDivs = document.querySelectorAll('div'); for (var i = 0, ilen = allDivs.length; i < ilen; i++) { /*NOOP*/ }
getElementsByTagName + length + for
const allDivs = document.getElementsByTagName('div'); for (var i = 0, ilen = allDivs.length; i < ilen; i++) { /*NOOP*/ }
querySelectorAll + dynamic length + for
const allDivs = document.querySelectorAll('div'); for (var i = 0; i < allDivs.length; i++) { /*NOOP*/ }
getElementsByTagName + dynamic length + for
const allDivs = document.getElementsByTagName('div'); for (var i = 0; i < allDivs.length; i++) { /*NOOP*/ }