Meta description length, duplicates and when Google ignores yours

1Check the description, and look for copies 1 minute

Open DevTools (F12), go to the Console and paste:

Copy// Checks this page's meta description, then compares it with up to 20 pages it links to
const clean = s => (s || '').replace(/\s+/g, ' ').trim();
const all = [...document.querySelectorAll('meta[name="description" i]')].map(m => clean(m.getAttribute('content')));
const desc = all[0] || '';
const ctx = document.createElement('canvas').getContext('2d');
ctx.font = '14px Arial';
const px = Math.round(ctx.measureText(desc).width);
const problems = [
  !desc && 'MISSING',
  all.length > 1 && 'MORE THAN ONE',
  desc && desc.toLowerCase() === clean(document.title).toLowerCase() && 'SAME AS THE TITLE',
  desc && desc.length < 70 && 'SHORT',
  (desc.length > 160 || px > 985) && 'LIKELY CUT OFF',
].filter(Boolean);
console.table({
  'Meta descriptions': all.length,
  Characters: desc.length,
  'Pixels (14px Arial, estimate)': px,
  Result: problems.join(', ') || 'ok',
});
// Duplicates: same description on other pages of the site. Skips sign-out, cart and delete links, and files.
if (desc) {
  const skip = /log[-_]?(out|off)|sign[-_]?(out|off)|delete|remove|unsubscribe|cart|basket|checkout|\.(pdf|zip|docx?|xlsx?|mp4|jpe?g|png|gif|webp)(\?|$)/i;
  const here = location.href.split('#')[0];
  const links = [...new Set([...document.links].map(a => a.href.split('#')[0])
    .filter(h => h.startsWith(location.origin + '/') && h !== here && !skip.test(h)))].slice(0, 20);
  const same = [], failed = [];
  for (const url of links) {
    try {
      const res = await fetch(url, { signal: AbortSignal.timeout(8000) });
      if (!res.ok || res.redirected || !/html/i.test(res.headers.get('content-type') || '')) {
        res.body?.cancel();
        failed.push(url);
        continue;
      }
      const doc = new DOMParser().parseFromString(await res.text(), 'text/html');
      if (clean(doc.querySelector('meta[name="description" i]')?.getAttribute('content')) === desc) same.push(url);
    } catch (e) { failed.push(url); }
  }
  console.log(same.length ? 'Same description on: ' + same.join(', ')
    : 'None of the ' + (links.length - failed.length) + ' linked pages checked share this description');
  if (failed.length) console.log('Skipped (error, redirect, timeout or not HTML): ' + failed.join(', '));
}

It reports how many descriptions the page has, the length in characters, an estimate of its width in Google's desktop results (14px Arial), and every problem it finds: missing, short, likely cut off or the same as the title. Then it fetches up to 20 same-site pages this one links to and lists any with exactly the same description.

It reads the page as rendered, so it includes a description added by JavaScript. The duplicate check reads each linked page's server HTML, so it misses descriptions added there by JavaScript. It skips sign-out, cart and delete links, files, and pages that fail or redirect, but every other link gets a normal request, so run it while signed out.

2See what Google actually shows 1 minute

Search Google for site: followed by the page's URL. Compare the snippet with your description. The snippet changes with the search, so also try a phrase people would use to find the page. If it's different text from the page, Google preferred that, so look at what it chose and why.

3Look at the source 30 seconds

Press Ctrl+U (⌘+⌥+U on a Mac) and search for name="description". There should be one match, in the head. A description added by JavaScript won't show here; the Console check above sees it.