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Social Preview Checker

Preview how a link looks on Facebook/Twitter/Zalo — check Open Graph, Twitter Card and hreflang

Why check the social share preview?

Missing or incorrect Open Graph tags make shared links look bad on social media — no image, wrong description — hurting click-through rate. The tool simulates the preview and lists every tag.

When a link is shared on Facebook, Zalo or Twitter/X, the platform reads Open Graph tags (og:title, og:description, og:image) and Twitter Card meta — not the actual page content — to build the preview. If these tags are missing, the platform picks a random image or paragraph from the page, which usually looks unprofessional and reduces click-through rate. The Social Preview Checker reads the page's OG and Twitter Card tags directly, rebuilds a Facebook-style preview so you can see it beforehand, and lists every declared hreflang pair (important for multilingual sites like vi/en) so you can quickly spot a missing language.

  • Simulates the preview like a Facebook share
  • Open Graph and Twitter Card checklist
  • Lists declared hreflang tags for multilingual SEO
Get started free
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How to use in 3 steps

  1. 1Enter the URL you want to preview before sharing.
  2. 2Click "Preview now" — the tool reads the OG/Twitter Card tags.
  3. 3Review the simulated preview, tag checklist and hreflang list.

Frequently asked questions

What size should og:image be?
Facebook recommends at least 1200×630px at a 1.91:1 ratio. Smaller images may appear blurry or get cropped in the preview.
Why does Zalo/Facebook show the wrong image when I share?
Usually because og:image is missing or the image URL fails to load (blocked by robots.txt, wrong path). The platform then picks a different image from the page.
Is Twitter Card required in addition to Open Graph?
Not required — if missing, Twitter/X falls back to Open Graph tags. But declaring twitter:card separately gives you more control over the preview format.
What is hreflang for?
It tells Google which language/region version of a page to show to which users, preventing different language versions from being flagged as duplicate content.