Twitter/X Card Preview & Validator

X's own official Card Validator now sits behind a developer account and login, which is a real barrier for checking a card before a page is even live, or for anyone who just wants a quick answer without setting one up. This tool checks a Twitter/X card against the actual spec, paste raw meta tags or fetch a live URL, and see both a rendered preview and a validation report covering the specific requirements for whichever card type is being used.

Why the fallback chain matters

X's card spec falls back to Open Graph tags for title, description, and image whenever the matching twitter: tag is missing, twitter:title falls back to og:title, and so on, which means a page can render a perfectly good card while relying entirely on Open Graph tags it happens to already have for Facebook. That's fine until those og: tags change or get removed for an unrelated reason, at which point the Twitter card silently breaks too, with no twitter: specific tag ever having existed to notice was gone. This tool shows exactly which source each resolved value came from, twitter:title itself or an og:title fallback, so that dependency is visible rather than hidden.

Real image dimension checking, not just presence

Confirming that twitter:image has a URL in it doesn't confirm the image is actually usable, an image that's too small will still get rejected or rendered poorly by X regardless of whether the tag technically exists. This tool loads the resolved image directly and reads its real dimensions, then checks those against the recommended minimum for the specific card type in use, roughly square and at least 144×144 for a summary card, at least 300×157 for the large image card. An image that fails to load is flagged separately from one that loads but is too small, since a failed load is often hotlink protection on the image's own server rather than a genuinely broken URL.

Different requirements for different card types

A player card and an app card have almost nothing in common with a summary card beyond sharing the same twitter:card tag namespace, a player card needs an https player URL plus explicit width and height, while an app card needs at least one platform specific app ID for iPhone, iPad, or Google Play. Checking every card type against the same generic rules would miss real, type-specific requirements, this tool branches its validation based on which card type is actually set, so a player card gets checked for a valid player URL rather than being told it's missing an image it was never going to use.

What this can't guarantee

X doesn't publish an exact current rendering specification, and its card layouts have changed before and will again, so the preview here is a close, genuinely useful approximation rather than a pixel-perfect simulation of what X will show today. Player cards also can't be meaningfully previewed at all, since that would mean actually embedding and running the player itself, the preview shows a placeholder instead and focuses on validating the required fields rather than rendering playback. For a final check on a page that's already live, there's no substitute for viewing an actual shared link or, for anyone with access, X's own developer tools.

Runs entirely in your browser

Pasted tags are parsed locally, and image dimension checks happen by loading the image directly in your browser rather than through a server. Fetching a URL does route through this site to retrieve that page's content, but nothing about the tags or images you're validating is uploaded anywhere. If you're setting up sharing tags for the first time rather than validating existing ones, our Open Graph Tags Generator is the better starting point, both part of the same Technical SEO collection this tool belongs to.