Social card preview

Paste a URL — or several, one per line — and see how each unfurls when shared on LinkedIn, Slack, X/Twitter, Facebook and iMessage. It reads each page’s live Open Graph and Twitter card tags.

How it works

It fetches the page, reads its Open Graph and Twitter-card tags — title, description, image — and shows the card at three sizes: large, compact, and the small thumbnail most feeds use. The checklist flags what’s missing or off: no image, a title that’ll truncate, an image that’s too small or the wrong shape.

Tips

  • Use a 1200×630 image (1.91:1).
  • Keep the title short — it has to read at thumbnail size.
  • Set a per-page image, not one site-wide default.
  • Re-scrape after changes; LinkedIn caches for about a week.

From a script or agent

It’s a plain JSON endpoint — point a script, a CI check, or an AI coding agent at it:

$ curl 'https://api.poly.io/og?url=https://example.com'

You get back the title, description, image and the same checks array shown above — enough to diagnose a card without leaving the terminal. See the API reference for every field, the diagnostics levels and limits.

Made by Polymorphism

We built this for ourselves. The rest of the time we build and run software for enterprises, the public sector and growing teams — that’s .

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