X / Twitter Card

X Cards (formerly Twitter Cards) are X's equivalent of Open Graph. They control how a shared link previews on X — with a large image, small image, video, or as plain text.

The main card types: summary (small image + text), summary_large_image (large image + text), player (video), and app (mobile app install). For most marketing links, summary_large_image is the highest-CTR choice.

X also reads Open Graph tags as a fallback — if you don't set explicit twitter: tags, X uses og: tags. Still, twitter:card is required, because without it X renders no card at all.