Social Preview Checker

See the card each platform builds from your Open Graph tags, and what is missing from them.

We fetch the page and its share image from our servers, and delete the run within the hour.

Frequently asked questions

What is a social preview?

The card a chat app or social network draws in place of a bare link: a picture, a headline and a line of description. Each one builds that card by fetching your page and reading its Open Graph meta tags.

How does this checker work?

Enter a URL and it is fetched on our servers. We read the og: and twitter: tags, download the share image to measure it, then draw the card X, LinkedIn, WhatsApp, Facebook, Slack and Discord would each build, and check what we found against the limits those platforms publish.

Which tags do I actually need?

Four, plus one. og:title, og:description, og:image and og:url feed every platform on this page. twitter:card is the fifth: it has no Open Graph equivalent, and X reads it to choose between the small card and the full-width image.

What do these platforms show when a page has no Open Graph tags?

Facebook's documentation says its crawler “uses internal heuristics to make a best guess about the title, description, and preview image” — the card still appears, but what is on it stops being your decision.

WhatsApp's documentation says it will “make the best attempt to show link previews, for example: relaxing requirements, looking for other HTML mark-ups and reverting to small link previews”, and adds that this “should not be relied on”.

LinkedIn asks for og:title, og:description, og:image and og:url and builds a plainer card without them. Slack's documentation says it looks for Open Graph and X card metadata and renders “some micro-approximation of the content”. X and Discord fall back to the page's <title>, and neither shows a picture without an image tag.

The short version: no platform shows nothing, and every one of them guesses differently. The previews on this page label which tag each line came from.

Do I need twitter: tags as well as og: tags?

Only twitter:card. X reads twitter:title, twitter:description and twitter:image first and falls back to the og: versions, so duplicating them buys nothing unless you want X to show something different from everywhere else.

What size should the share image be?

1200×630, at a 1.91:1 ratio. Facebook's image guidelines ask for at least 1200×630, put the minimum allowed dimension at 200×200 and the maximum file size at 8 MB. WhatsApp is the tight one: its documentation asks for images under 600 KB, so a heavy hero image is the usual reason a preview arrives with no picture.

Why does X show my link as a picture with no description?

That is the large-image card as X draws it now. Since 2024 it prints the headline over the bottom of the picture and does not show the description at all, so anything in the lower fifth of your image sits under text. The small summary card still shows a description; the preview on this page follows whichever twitter:card value you declare.

Why has the preview not changed after I fixed my tags?

Every platform caches what it scraped, and some of them hold a failed scrape for a long time. Facebook's Sharing Debugger and LinkedIn's Post Inspector both re-fetch a URL on demand and are the way to clear that. This tool always fetches your page fresh, so it shows the tags as they are now.

How close are these previews to the real thing?

The X, Slack and Discord cards are drawn from measurements taken out of those products' own stylesheets — frame, radius, padding, type sizes, colours and where each line is cut. Slack's unfurl, for instance, is a rounded card with a one-line title, not the coloured bar it used to be.

Facebook, LinkedIn and WhatsApp only render behind a login, so we cannot measure them. Those three follow each platform's published specifications and are the least exact of the six.

Every platform also redesigns without notice, renders differently on a phone, and may fall back to its own guess. Treat the cut-off as a good estimate rather than a promise.

Do you store the URLs I check?

No. The run is deleted within the hour, and nothing is saved in your browser.

Is it free?

Yes. There is no account and nothing to install.

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