Facebook link preview checker
Facebook builds link cards from Open Graph tags fetched by facebookexternalhit. The same cache is shared by Messenger and Instagram DMs.
Tags Facebook reads
| Field | Tags, in fallback order |
|---|---|
| Title | og:title → <title> |
| Description | og:description → meta description |
| Image | og:image → og:image:secure_url |
Image requirements
| Recommended | 1200×630 (1.91:1) |
|---|---|
| Minimum | 200×200 |
| Maximum weight | 8 MB |
| Formats | JPEG, PNG, GIF, WebP |
Card layout
Images at least 600 px wide with a landscape ratio show as a large card. Smaller or square images show as a small thumbnail beside the text.
How to refresh the Facebook preview cache
Open the Facebook Sharing Debugger, paste the URL and click Scrape Again.
Common problems
- The image is missing on the first share: add og:image:width and og:image:height so Facebook does not have to download the image first.
- Old title or image: the preview is cached. Scrape it again in the Sharing Debugger.
- Relative og:image paths are ignored. Always use an absolute URL.
Rule confidence: documented.