Snippet to list the link elements with some web performance "rel" attribute

list-link-rels.js

const rels = ['preload', 'prefetch', 'preconnect', 'dns-prefetch', 'prerender', 'modulepreload']

rels.forEach(element => {
  const linkElements = document.querySelectorAll(`link[rel="${element}"]`)
  const dot = linkElements.length > 0 ? '🟩' : '🟥'
  console.log(`${dot} ${element}`)
  linkElements.forEach(el => console.log(el))
});