Open Graph preview: see the card before you paste it
How a URL renders in Slack, LinkedIn, Facebook, X and iMessage, and which tags are missing. The images come from the site itself, so a broken one looks broken here too.
The two failures worth an afternoon
- No image at all. Every link to the site, in every chat, for as long as that stays true, is a grey rectangle. It is one tag.
- One image for the whole site. Common on WordPress and on most builders — the theme sets a default and no page overrides it, so every article shares a logo card. Better than nothing, and a per-page image is why some links get clicked.
Honest scope
This is a tool about how links look to people. The rest of the head — title, description, canonical, how much text is actually in the HTML — is what the website metadata checker reads. Neither is about whether an answer engine names your client — that is decided by whether a page exists that answers the question being asked, which is what the report measures. We keep them apart on purpose.
FAQ
Questions
- Which tags actually matter?
- og:title, og:description and og:image carry almost all of it, and og:image carries most of that — it is the difference between a link that occupies half a phone screen and one that looks like a grey box. twitter:card set to summary_large_image is worth adding on top.
- What size should the image be?
- 1200×630 is the safe default; it is the 1.91:1 ratio most platforms crop to. Keep important detail away from the edges, because several platforms crop differently, and keep the file well under a megabyte so the unfurler does not give up.
- My image shows here but not in Slack.
- Usually caching. Platforms cache an unfurl for a long time, and if they fetched your page before the image existed they will keep showing the old card. Facebook and LinkedIn both publish a debugger that forces a refresh; X refreshes on its own eventually.
- Why is my image blank in the preview?
- Because it is blank in reality. The images here are loaded straight from your site by your browser, exactly as an unfurler fetches them — so a hotlink block or a 404 shows up here as it would there. That is the point of not proxying them. A relative image URL is the one thing we resolve, so you can see the picture, and it is flagged, because most unfurlers will not.
- Do I need og:url?
- It helps: it tells platforms which URL to treat as canonical when the same page is reachable several ways, so shares of /page?ref=twitter and /page consolidate. Make sure it points at your own origin.
- Does any of this affect AI search?
- Not directly. Open Graph tags are for the humans who paste your link. They matter to your funnel rather than to what an answer engine cites — worth an hour, not worth a week.
See who the engines recommend instead
The prompts your client loses, who wins them, and the tasks that would change it.