What Open Graph does
Open Graph is the set of og: meta tags Facebook introduced and almost every app now reads: LinkedIn, Slack, Discord, iMessage, WhatsApp and X. When someone pastes your link, the app fetches the page, reads these tags and draws a card. Without them it guesses, usually with the wrong image and a title pulled from your navigation.
The tags you need
- og:title is the card headline. It can be punchier than your SEO title, since there is no keyword to match.
- og:description is one or two lines under it. Many apps show only the first line.
- og:image is the picture, and the part people actually notice. Use 1200x630 pixels (a 1.91:1 ratio), keep important text away from the edges, and stay under 5 MB.
- og:url is the canonical address, so shares of different variants count as one.
- og:type is
websitefor most pages andarticlefor blog posts. - twitter:card picks the X layout.
summary_large_imageshows a big image;summaryshows a square thumbnail.
X reads og:title, og:description and og:image when its own twitter: tags are missing, so you do not need to duplicate them.
Why the preview might not match
Each app crops and styles cards differently and caches them for days. If you change the image after sharing, run the URL through the platform's own debugger (Facebook Sharing Debugger, LinkedIn Post Inspector) to refresh it. The image must be publicly reachable: images behind a login, on localhost or blocked by robots.txt will not load for the crawler.
Make the image
No share image yet? The OG image generator makes a clean 1200x630 card from a title and your logo. Once the page is live, confirm what crawlers see with the Open Graph checker.