CardScopeFree check
Mastodon link preview checker
Checks the title and image Mastodon reads.
Uses the email from Checkout. If that address paid, we send the same key.
What Mastodon reads
From this fetch. Not a Mastodon server’s preview.
Mastodon preview
Mastodon’s LinkDetailsExtractor prefers a JSON-LD headline, then og:title, then the page title. The description follows the same order. The image is og:image only: JPEG, PNG, GIF, or WebP, under 8 MB. The default stylesheet crops that image to a square and clips the title and the description to one line. No title means no card. When the page has an oEmbed link, Mastodon asks that endpoint first. This check does not call it, and the card says so.
Each server fetches the page itself and stores one card per URL. Servers run different versions, so a real post is the final check. This page reads the live HTML. It does not refresh a card a server already stored, and it is not a Mastodon product. The author byline (fediverse:creator) is separate from the link card. A paid check draws this Mastodon card from the tags above. Mastodon link preview