See how any link looks when shared on X, Facebook, LinkedIn and Slack, using the page's Open Graph and Twitter tags, before you post it.
How to use the Open Graph preview
- Enter a URL.
- See the card for each network and the tags it was built from.
- Fix a missing image, title or description, then re-check.
The tags that build the card
og:title, og:description, og:image (1200×630 works everywhere) and og:url, plus twitter:card set to summary_large_image for a big image on X. Without them, networks guess and often pick the wrong image.
Reading the previews
If anything is missing, a note at the top lists it: og:title, og:description, og:image, og:url or twitter:card. The four cards show roughly how each network lays the link out. X and LinkedIn show the image and title, Facebook adds a line of description, and Slack and Discord show site name, title, description and a smaller image. When an OG tag is missing we fall back to the Twitter tag and then to the page title or description, like most networks do, so a card can look fine here while a tag is still missing. "No og:image" means every share will be a bare text link.
Why cards break
The og:image URL is relative (/og.png) instead of a full https address. The image is too small, so networks show a tiny thumbnail instead of a large card; 1200×630 is the safe size. The image is behind a login or blocked by robots.txt. The page sets tags with JavaScript after load, which most link crawlers never run. Or the title is very long and gets cut after one line on LinkedIn and X.