Free Twitter Card Validator
Preview how your URL renders as an X Card. Validate twitter:card, twitter:image, and OG fallback tags in one click.
X's official cards-dev.x.com validator is broken. This is a working replacement.
What is a Twitter Card?
A Twitter Card (officially renamed to X Card after the 2023 rebrand, though most developers and SEO tools still call them Twitter Cards) is a rich media preview that displays when someone shares a URL on X / Twitter. Instead of a bare URL, your link unfurls into a styled card with an image, title, description, and domain, dramatically improving click-through rate.
There are four card types, controlled by the twitter:card meta tag:
- summary: small square thumbnail (144x144 min) beside the title and description. Best for short content and link aggregators.
- summary_large_image: large hero image (1200x628 recommended) above the title. The default for most blogs, articles, and product pages.
- player: embedded audio/video player. Requires HTTPS, an iframe URL, and approval from X via the developer portal.
- app: mobile app install card, deep-linking to iOS or Android app stores.
Most modern sites use summary_large_image because the larger visual tends to win more clicks than the small summary card. If you're also publishing to other networks, our free OG image checker validates the Open Graph tags that Facebook, LinkedIn, and Slack use.
Twitter Card Image Size Requirements 2026
| Card type | Min size | Recommended | Aspect ratio |
|---|---|---|---|
| summary | 144x144 | 400x400 | 1:1 |
| summary_large_image | 300x157 | 1200x628 | 1.91:1 |
| player | 262x262 | 640x640 | 1:1 |
| app | App icon | Auto | N/A |
Max file size: 5MB for static JPG/PNG/WEBP, 15MB for animated GIF. All images must be served over HTTPS; http:// URLs are silently rejected by X. Need exact dimensions for every platform? Check our 2026 social media image sizes guide, or resize an image to fit X's spec with our X image resizer.
Twitter Card Meta Tag Reference
Drop these tags into the <head> of your HTML. At minimum, set twitter:card and an image; everything else has sensible fallbacks via Open Graph.
<!-- Required -->
<meta name="twitter:card" content="summary_large_image" />
<!-- Strongly recommended -->
<meta name="twitter:title" content="Your post title (≤ 70 chars)" />
<meta name="twitter:description" content="A compelling summary (≤ 200 chars)" />
<meta name="twitter:image" content="https://example.com/preview.jpg" />
<meta name="twitter:image:alt" content="Descriptive alt text for accessibility" />
<!-- Optional but useful -->
<meta name="twitter:site" content="@yourbrand" />
<meta name="twitter:creator" content="@author" />
<!-- Open Graph fallbacks (X uses these if twitter:* missing) -->
<meta property="og:title" content="Your post title" />
<meta property="og:description" content="A compelling summary" />
<meta property="og:image" content="https://example.com/preview.jpg" />
<meta property="og:url" content="https://example.com/this-page" />
<meta property="og:type" content="article" />If you're writing X content regularly, save the boilerplate above as a snippet, and use our X post generator or X thread maker to draft the copy that goes with each shared link.
Why X's Official Validator Stopped Working
The official Twitter Card validator lived at cards-dev.twitter.com/validator for nearly a decade. After Twitter rebranded to X in 2023, the URL was redirected to cards-dev.x.com, but the tool itself was deprecated. Today it either returns errors, redirects you to a login wall, or fails to render previews even when your tags are perfect.
X has not released a replacement. They also removed the "preview card" feature from the X Developer Portal and the "Refresh card cache" option that used to let publishers force a re-crawl. The community has been complaining since 2023, but X has shown no signs of restoring the validator.
This free tool fills that gap. It parses your page's twitter:* and og:* meta tags server-side, applies X's documented fallback rules, and renders a faithful visual preview of both card layouts. If you're building a content workflow that publishes to multiple networks, our social media scheduler lets you review each post before it goes out.
Troubleshooting Twitter Cards Not Showing
1. X cached an old preview
X cards typically cache for 7 days. There's no manual refresh since cards-dev was retired. Workaround: append ?v=2 to your URL when sharing, or wait it out. Always validate before first share.
2. Robots.txt is blocking Twitterbot
X uses a crawler called Twitterbot to fetch meta tags. If your robots.txt disallows it, no card will render. Check that your robots.txt allows Twitterbot user-agent or doesn't block / globally.
3. Image dimensions are wrong
Images below the minimum size (144x144 for summary, 300x157 for summary_large_image) are silently rejected. Files over 5MB fail too. Resize with our X image resizer or use 1200x628 to stay safely within spec.
4. Meta tags are missing or malformed
Common mistakes: using property="twitter:card" instead of name="twitter:card", omitting the twitter:image tag entirely, or pointing to a relative image URL. Always use absolute HTTPS URLs and the name= attribute for Twitter tags.
5. Your URL redirects and X is caching the wrong target
If example.com/page redirects to example.com/page/, X may have cached the meta tags from the redirect destination only. Make sure both URLs return identical meta tags, or set up a canonical that always resolves to the live page.
Need help managing the full publishing workflow? Our X scheduler lets you review each post and schedule it across your X accounts. Pair it with our X bio generator if you're also optimising your profile.
More Resources
How to Use the Twitter Card Validator
Paste your URL
Drop the full URL of any page (including https://). The tool fetches the live HTML and parses every twitter:* and og:* meta tag.
Review the preview
See how your link renders as a Twitter Card on X, with a full table of detected tags and character counts. Free validator, no signup.
Fix the issues shown
Address any red errors or amber warnings, redeploy, and validate again. Cards usually update on X within 7 days (no manual refresh available).
Twitter Card Validator FAQ
What is a Twitter Card?
A Twitter Card (now called X Card after the 2023 rebrand) is the rich preview that unfurls when you share a URL on X. There are four types: summary, summary_large_image, player, app, controlled by the twitter:card meta tag in your page head.
Why isn't my Twitter Card showing on X?
The five most common causes: (1) twitter:image is missing or broken, (2) the image is below minimum size (144x144 summary, 300x157 large image), (3) robots.txt is blocking the Twitterbot crawler, (4) X cached an old version (no manual refresh since cards-dev.x.com was retired), or (5) your URL redirects and X is caching the wrong target. Validate first, then share.
What size should Twitter Card images be?
For summary_large_image, use 1200x628px (1.91:1 ratio), the same as Facebook OG. For summary cards, use at least 144x144px (1:1 recommended). Max file size 5MB for static, 15MB for GIF. JPG, PNG, WEBP, and GIF supported. Always serve over HTTPS. X silently rejects http:// images.
What's the difference between summary and summary_large_image?
Summary shows a small square thumbnail (144x144 minimum) on the left of the title and description: compact, best for link aggregators. summary_large_image shows a large hero image (1200x628) above the title and description: best for blogs, articles, and product pages. Most modern sites use summary_large_image because it drives 2-3x higher click-through.
Can I force X to refresh a cached Twitter Card?
No. X removed the manual refresh feature when they shut down cards-dev.x.com. Card cache typically clears in 7 days. Workarounds: append ?v=2 to the URL when re-sharing, share from a verified/paid account (sometimes triggers re-crawl), or wait it out. Always validate tags before the very first share.
Do I need both Twitter Card tags and Open Graph tags?
No, X falls back to Open Graph (og:title, og:description, og:image) when twitter:* tags are missing. If your OG tags are well-configured, X will use them. Adding twitter:* tags is useful when you want a different image, title, or description specifically for X (versus Facebook/LinkedIn). At minimum, set twitter:card so X knows which layout to render.
Is X's official Twitter Card validator still working?
No. The cards-dev.x.com (formerly cards-dev.twitter.com) validator was deprecated when Twitter became X in 2023. It returns errors, shows a login wall, or fails to render previews. X has not released a public replacement. This tool fills the gap by parsing your meta tags and rendering a faithful card preview.
What meta tags are required for Twitter Cards?
Only twitter:card is strictly required (set to summary, summary_large_image, player, or app). Strongly recommended: twitter:title, twitter:description, twitter:image. Optional but useful: twitter:site (your @handle), twitter:creator (author @handle), twitter:image:alt (accessibility). If twitter:* tags are missing, X falls back to og:title, og:description, og:image.