Twitter Card validator: preview your Twitter/X link cards

The request uses the header 'Twitterbot/1.0'. From the returned HTML we collect the twitter: tags and the Open Graph tags, then draw the card from them.

Twitterbot looks for twitter:title, twitter:description and twitter:image first and falls back to the og: equivalents when they are absent, so a page with complete Open Graph tags needs only twitter:card added to choose a layout. With 'summary_large_image' the image is shown full width at roughly 2:1; with 'summary' it becomes a small square thumbnail beside the text.

X refreshes the card data it holds for a URL roughly once a week, so a corrected page can keep showing the old card for a while. Two checks catch most failures. The image URL must be absolute and allowed by your robots.txt, because Twitterbot obeys robots.txt when it fetches both the page and the image. And the page must return its tags to a client that sends no cookies and runs no scripts, which is exactly the request this test makes.

When a link is shared on Twitter/X, Twitterbot fetches the page to generate a Twitter Card - the preview box that appears below the tweet showing a title, description, and image. Twitter Cards significantly increase engagement: tweets with cards receive substantially more clicks, retweets, and likes than plain text tweets with URLs.

Twitterbot does not execute JavaScript. It reads Twitter Card meta tags (twitter:card, twitter:title, twitter:description, twitter:image) and Open Graph tags as fallbacks from the raw HTML response. If your JavaScript framework injects these tags client-side, Twitterbot sees nothing and your tweets display as bare URLs.

Twitter/X supports several card types: summary (small image), summary_large_image (full-width image), player (embedded video), and app (mobile app install). The summary_large_image format is most commonly used and requires twitter:card set to 'summary_large_image' along with a twitter:image pointing to an image at least 300x157 pixels.

Pre-rendering ensures Twitterbot receives your Twitter Card and OG tags in the raw HTML, producing rich, visually engaging tweet cards that drive clicks and engagement.