The four twitter:card types X supports
- summary — small square image on the left, title and description on the right. The default if
twitter:cardis missing. - summary_large_image — full-width image above the title. This is what most sites want — it takes up more space in the timeline and gets more clicks.
- player — embeds an iframe (for video or audio). Requires
twitter:player,twitter:player:width, andtwitter:player:height. - app — renders an app-install card with App Store / Play Store links. Rarely used since Twitter removed the old app card rendering.