Run results for: TreeWalker/ filter vs querySelectorAll vs NodeIterator /filter

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.5 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one month ago

Test name	Executions per second
TreeWalker	187702.7 Ops/sec
querySelectorAll	430997.2 Ops/sec
NodeIterator	175813.0 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 filter = function(node) { return node.tagName == "H1" ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_SKIP; }; const walker = document.createTreeWalker( document.body, NodeFilter.SHOW_ELEMENT, filter, false ); for (let node = walker.nextNode(), i = 0; node; i++, node= walker.nextNode() ) { node.className = 'classy' ; }
querySelectorAll
const elements = Array.from(document.body.querySelectorAll('h1')) for(let el of elements){el.className = 'classy'}
NodeIterator
const filter = function(node) { return node.tagName == "H1" ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_SKIP; }; const walker = document.createNodeIterator( document.body, NodeFilter.SHOW_ELEMENT, filter, false ); for (let node = walker.nextNode(), i = 0; node; i++, node= walker.nextNode() ) { node.className = 'classy' ; }