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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36

Browser: Chrome 143

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 8 months ago

Benchmark engine: Benchmark.js

Test name	Executions per second
✓ getElementsByTagName + length + for	39,503,312 Ops/sec
getElementsByTagName + dynamic length + for	7,647,957 Ops/sec
querySelectorAll + length + for	6,230,052 Ops/sec
querySelectorAll + dynamic length + for	4,216,176 Ops/sec
querySelectorAll + forEach	1,390,466 Ops/sec
getElementsByTagName + Array.from + forEach	1,095,003 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*/ }