What is a Twitter Card
A Twitter Card is the rich preview that shows up when someone shares a link on X (formerly Twitter). Without it, your link appears as plain text. With it, you get image, title and description — far more attention-grabbing in the feed.
Card types
- summary: small square thumbnail next to the title. Good for sites where the image is not the focus.
- summary_large_image: large horizontal image above the title. Default choice for most landings and articles.
- player: for embedded video or audio. Requires Twitter approval.
- app: to promote mobile apps with a direct link to the store.
Image sizes
For summary_large_image: 1200x628 pixels, 1.91:1 ratio, minimum 300x157, max 5 MB. JPG, PNG, WebP or static GIF. For summary: minimum 144x144, 1:1 ratio.
How Twitter detects your card
Twitter uses a bot called Twitterbot that fetches your URL and parses the meta tags. If your robots.txt blocks Twitterbot, no card. No card either if the server returns 4xx/5xx, if the page is too slow, or if meta tags are malformed.
Open Graph as fallback
Twitter is smart: if it does not find meta name="twitter:..." but does find meta property="og:..." (Open Graph), it uses OG as fallback. So if you already set OG properly, Twitter Card works even without specific tags. Twitter-specific tags only override OG when you want to show something different on X than on Facebook or LinkedIn.
Validation and debug
Twitter changed its historical validator, but you can test by pasting your URL in a draft tweet and checking the preview. If no card: confirm the image is publicly reachable, the HTML has the meta tags, the site returns 200, and clear cache if the image was recently changed.
Common mistakes
- Relative image URL: use absolute URLs (with https://), never relative paths.
- Image behind auth: the image must be public.
- Wrong type: if you do not specify summary_large_image, X falls back to summary.
- Cache: og:image changes can take time to propagate.