Meta tags are the part of a page nobody looks at until a link preview shows up blank in Slack, or Search Console says 400 pages have duplicate titles. Browser extensions check one page at a time. This post builds a script that checks a whole list and writes one CSV row per page, with a plain list of what's wrong.

What gets checked

Check Why it matters

Missing or long <title> (over ~60 chars) Search results truncate it, and it's still the strongest on-page signal.

Missing description, or outside ~70-160 chars Google often rewrites it anyway, but a missing one means it picks random page text.

No canonical, or more than one different canonical Duplicate URLs (tracking params, www , trailing slashes) split ranking signals.

noindex in meta robots or the X-Robots-Tag header The classic "why did this page vanish" bug after a staging deploy.

Zero, several or empty <h1> Not a ranking rule, but a reliable sign of a template problem.

Missing og:title / og:image , or an og:image that doesn't load Blank or broken…