OG Tag Checker
Test the Open Graph and Twitter Card tags on any public URL. We validate the exact tags Facebook, LinkedIn, Slack, X, Discord and iMessage read when your link is shared, and show you the same preview cards those platforms will render.
Example checks
Real-world sites, pre-rendered so you can see what a healthy Open Graph setup looks like — and where the edge cases hide.
- GitHub — github.comView →
Reference implementation from a top-100 site — clean og:image, twitter:card set correctly.
- Vercel — vercel.comView →
Programmatic OG images via @vercel/og — a good example of dynamic per-page previews.
- Stripe — stripe.comView →
Marketing site with polished cards, well-tuned title/description length.
- Tailwind CSS — tailwindcss.comView →
Docs-first product with a strong branded card and per-page overrides.
- Next.js — nextjs.orgView →
Framework homepage — see how og:image, og:type, and twitter:card combine.
- OpenAI — openai.comView →
Large brand with strict og:image sizing and site_name usage.
What we check
- Required Open Graph tags:
og:title,og:description,og:image,og:url,og:type. - Twitter Card metadata (
twitter:card,twitter:image) and fallback behavior. - Image URL reachability, HTTPS, and content-type.
- Length limits for title & description that survive LinkedIn/Slack truncation.
- Canonical URL and basic
<title>/ description presence.
Frequently asked questions
What does the OG tag checker do?
It fetches a public URL, parses every Open Graph and Twitter Card meta tag in the HTML, validates them against Facebook, LinkedIn, X and Slack requirements, and previews how the link will render when shared.
Which Open Graph tags does it validate?
og:title, og:description, og:image, og:url, og:type and og:site_name for Open Graph; twitter:card, twitter:title, twitter:description and twitter:image for X. It also flags missing <title>, description and canonical.
What are the recommended og:image dimensions?
1200×630 (1.91:1) is the safe target — Facebook, LinkedIn, X summary_large_image and Slack all render that size cleanly. Absolute HTTPS URLs are required; relative paths and http:// images are silently dropped by LinkedIn and X.
Why don't my Open Graph tags update on LinkedIn or Facebook?
Every platform caches the preview it last scraped. Force a refresh in LinkedIn Post Inspector, the Facebook Sharing Debugger, or by adding a cache-busting query string to og:image. Slack respects the debug re-scrape within minutes.
Is this a free Open Graph debugger?
Yes. ogimagex is free and open source. There is no signup, no rate wall for casual use, and no server-side storage of the URLs you check.
What's the difference between og:image and twitter:image?
twitter:image overrides og:image only when a twitter:card is set. If you only set og:image, X will fall back to it as long as twitter:card exists (usually 'summary_large_image').
How long can og:title and og:description be?
Aim for og:title ≤ 60 characters and og:description ≤ 155 characters so LinkedIn and Slack don't truncate mid-word. The checker warns above 70 / 200.