Free tool · no signupTwitter Card validator
X removed the preview from its own Card Validator and never shipped a replacement, which is why so many guides still send you to a page that no longer shows you anything. Paste a URL here to see the card X will render and every tag it reads to build it.
How X renders a link
X reads Twitter Card tags first and falls back to Open Graph, so a page with only og: tags still works. The one tag that decides everything is twitter:card. Set it to summary_large_image and you get the full-width card with the image on top, the domain, the title, and a couple of lines of description. Leave it out and X renders the small square summary card no matter how good your image is, which is the difference between a post that stops the scroll and one that does not.
How to see the live card, now that the validator is gone
X caches cards aggressively and offers no public way to force a refresh. The official workaround is to paste the link into the post composer and look at the preview it generates without sending the post — that reflects what X currently has cached. Changing the tags on a page X has already scraped can take a while to show up, and there is no button to hurry it along. If the URL is one you can change, posting a fresh URL is the fastest route to a fresh card.
Checking every platform at once instead? Use the full Open Graph checker, or read Getting the right link preview on X and Open Graph image sizes, by platform.
Frequently asked questions
- Does the Twitter Card Validator still work?
- Not for previews. X stripped the preview out of cards-dev.twitter.com/validator and has not replaced it, so the tool most articles still recommend cannot show you your card. X's own guidance is to use the post composer instead. Third-party checkers like this one read the same tags Twitterbot reads and render the card from them.
- Why is my card showing as a small square instead of large?
- twitter:card is either missing or not set to summary_large_image. X falls back to the compact summary card whenever it is unsure. The other cause is an image below 600×315, which X will not use for a full-width card even when the tag is correct.
- Do I need Twitter Card tags if I already have og: tags?
- You need twitter:card. X will read og:title, og:description, and og:image happily, but it decides between the large and small card layout from twitter:card alone, and the default is small. Everything else can come from your Open Graph tags.
- What image size works best on X?
- 1200×628, or 1.91:1. The hard floor for the full-width card is 600×315. Use PNG or JPEG; X does not render SVG previews.