https://stackoverflow.com/a/68335748/5251465

commits_of_forks.js

javascript:(async () => {
  /* while on the forks page, collect all the hrefs and pop off the first one (original repo) */
  const aTags = [...document.querySelectorAll('div.repo a:last-of-type')].slice(1);

  for (const aTag of aTags) {
    /* fetch the forked repo as html, search for the "This branch is [n commits ahead,] [m commits behind]", print it directly onto the web page */
    await fetch(aTag.href)
      .then(x => x.text())
      .then(html => aTag.outerHTML += `${html.match(/This branch is.*/).pop().replace('This branch is', '').replace(/([0-9]+ commits? ahead)/, '<font color="#0c0">$1</font>').replace(/([0-9]+ commits? behind)/, '<font color="red">$1</font>')}`)
      .catch(console.error);
  }
})();