Run results for: TreeWalker vs querySelectorAll vs NodeIterator filters

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36

Browser: Chrome 102

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
TreeWalker	90784.4 Ops/sec
querySelectorAll	113887.1 Ops/sec
NodeIterator	52855.3 Ops/sec

HTML Preparation code:

<!-- article out start -->
<article>
  <!-- article in start -->
  <h1>Lorem ipsum</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
  <!-- article in end -->
</article>
<!-- article out end -->

<!-- article out start -->
<article>
  <!-- article in start -->
  <h1>Lorem ipsum</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
  <!-- article in end -->
</article>
<!-- article out end -->

<!-- article out start -->
<article>
  <!-- article in start -->
  <h1>Lorem ipsum</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
  <!-- article in end -->
</article>
<!-- article out end -->

Tests:

TreeWalker
const walker = document.createTreeWalker( document.body, NodeFilter.SHOW_ELEMENT, ); for (let node = walker.nextNode(), i = 0; node; i++, node= walker.nextNode() ) { if(node.nodeName == 'H1') node.className = 'classy' ; }
querySelectorAll
const elements = Array.from(document.body.querySelectorAll('h1')) for(let i = 0, len = elements.length; i < len; i++){elements[i].className = 'classy'}
NodeIterator
const walker = document.createNodeIterator( document.body, NodeFilter.SHOW_ELEMENT, ); for (let node = walker.nextNode(), i = 0; node; i++, node= walker.nextNode() ) { node.className = 'classy' ; }