What is a Twitter card?
A Twitter card (also called an X card or link preview) is the rich unfurled preview that appears under a tweet when you share a URL on X. Instead of a bare link, the post shows the page's title, description, and image as a tappable card. The card is built from twitter: and Open Graph (og:) meta tags in the page's HTML.
How to validate a Twitter card
Paste any public URL into the box above. Keep fetches the page, reads the meta tags, and renders the exact card X would display. You also get a checklist showing which twitter: and og: tags are present, plus the resolved URL after redirects. No login, API key, or X account is required.
Twitter card types
X supports four card types, declared with the twitter:card meta tag:
- summary: small thumbnail card with a square image beside the title and description.
- summary_large_image: full-width image card with the title and description below. The most common card on X today.
- app: direct download card for iOS and Android apps.
- player: embedded audio or video player card.
The Twitter card meta tags X reads
At a minimum, X needs twitter:card set to summary or summary_large_image. Everything else falls back to the matching Open Graph tag, so you usually only need the OG set unless you want different copy on X versus other platforms.
twitter:card: required. Sets the layout. Falls back tosummaryif missing.twitter:title: falls back toog:title, then the<title>tag.twitter:description: falls back toog:description, then<meta name="description">.twitter:image: falls back toog:image. JPG, PNG, WebP, and GIF only. Under 5MB. At least 300×157 for the large card.twitter:siteandtwitter:creator: optional. The @handle of the publisher and author.
Why the official Twitter Card Validator is gone
X retired cards-dev.twitter.com/validator in 2023 along with most of the developer-facing tooling. Cards still work the same way, the meta tags X reads have not changed, and X still caches link previews aggressively. The validator above replaces the official debugger by fetching the live page and rendering the same card X would.
When you'd need one
- Shipping a new landing page or blog post and confirming the card looks right before tweeting it
- Debugging why an old URL is still showing the wrong image (usually X's cache, not your tags)
- Choosing between the small summary card and summary_large_image for a campaign
- Auditing a site's social meta tags across pages
- Comparing what X sees against what your CMS thinks it set
Frequently asked questions
Is this Twitter card validator really free?
Yes. There is no sign-up, no paywall, and no per-URL limit. Paste any public URL and the validator returns the preview straight away.
Why did X retire the official Card Validator?
X (formerly Twitter) shut down the cards-dev.twitter.com debugger in 2023. Cards still render on X exactly as they used to, but the official validator is gone, which is why standalone tools like this one exist.
What card types does X support?
X supports four card types via the twitter:card meta tag: summary (small thumbnail card), summary_large_image (full-width image card), app (iOS or Android app card), and player (audio or video card). The two used by the vast majority of sites are summary and summary_large_image.
My twitter:image is set, why does the preview still look small?
X falls back to the small summary card when the twitter:card tag is missing, when it reads summary, or when the image fails validation. To get the wide card, set twitter:card to summary_large_image and make sure the image is at least 300×157 pixels and under 5MB.
Do I need both og: and twitter: meta tags?
No, and you should not set both. Open Graph (og:) tags work everywhere. X, LinkedIn, Slack, Discord, Facebook, and iMessage all read them, so set them once and every platform unfurls correctly. The only X-specific tag worth adding is twitter:card, which picks between the small thumbnail (summary) and the large image card (summary_large_image). X falls back to your og:title, og:description, and og:image automatically. Setting both means twice the work and twice the chances of the two sets drifting apart.
What image size should I use for a Twitter card?
For summary_large_image, X recommends a 2:1 ratio (1200×600 is a safe default) at less than 5MB. For the small summary card, the image is cropped to a square thumbnail, so 1:1 (400×400 minimum) works best. JPG, PNG, WebP, and GIF are supported.
Why is the validator showing a card when X shows a plain link?
X caches link previews aggressively. When you change a card and tweet the URL again, X may serve the old preview for hours. The validator always fetches the live page, so the difference is usually X's cache, not your tags.
Does the validator work for sites that block bots?
It uses a Twitterbot-style user agent and follows redirects, so most public sites work. Sites that require a login, gate content with Cloudflare challenges, or block all crawlers will return an error.
Save posts, threads, and profiles in Keep
Keep turns the things you bookmark on X, like threads, replies, and long posts, into clean, searchable Markdown you can read later or hand to your AI agent. Connect your X account once and every new bookmark syncs automatically.