Twitter Card Validator: Test Your X Link Previews for Free

You are about to share a link on X. You have spent an hour on the perfect og:image, triple-checked the title, and the description reads like ad copy. You post it — and the card shows a tiny thumbnail instead of the full-width image you designed. Or worse, no card at all.

X’s original Card Validator — the tool everyone used to catch this before posting — was shut down when Twitter rebranded to X. The developer portal has a replacement, but it requires a developer account and a multi-step setup. Most people just post and hope.

We built this page to fill that gap. While building the OG Image Checker we ran it against our own launch pages, our competitors’ pages, and every site in our examples gallery — catching missing twitter:card tags on sites that looked perfectly fine in the browser. The tool below is that same engine, free: paste any URL, see your X card rendered exactly as it will appear in the timeline, and audit every tag behind it. This twitter card validator is free, online, and needs no account, key, or setup.

Why X cards break (the short version)

Before using the validator, it helps to know what it checks. How does twitter card work, end to end? X builds its card from two families of meta tags — twitter:* (X-specific) and og:* (Open Graph, the universal standard). When either set has a problem, the card degrades or disappears.

The five failures behind almost every “twitter card not showing” report:

1. twitter:card is missing. Without it, X silently defaults to the small summary format — your 1200×600 image becomes a 100px thumbnail. This single line fixes it:

   <meta name="twitter:card" content="summary_large_image" />

2. og:image is missing or invalid. X falls back to og:image when twitter:image is absent. If og:image points to a relative path (/og.png) or returns a 404, there is no image to render.
3. The image is over 5 MB. X refuses to display it. The right twitter card image size is 1200×600 (2:1 ratio) under 5 MB — our size guide covers every platform. Compress before posting — our OG Image Generator exports at 50–150 KB in JPG format.
4. The tags are rendered by JavaScript. X’s crawler does not execute JS. If your meta tags only appear after a React/Vue hydration, the crawler sees an empty head. The tags must be in the server-rendered HTML.
5. Stale cache. X snapshots your card the first time the link is shared and keeps it for days. After fixing your tags, the old card may persist — force a re-crawl by sharing a new post (not a retweet).

For a deeper explanation of each — including the code and the specific fix — see our Twitter Cards: The Complete Guide.

How to validate a Twitter Card (3 steps)

1. Paste your URL into the OG Image Checker above. It fetches your live page the way X’s crawler does — server-side, no JavaScript execution.
2. Check the X preview card. The tool renders your card in the timeline format: full-width image, title, description, domain. If the card looks wrong here, it will look wrong on X.
3. Scan the audit table. Every twitter:* and og:* tag gets a pass / warn / fail verdict. The most common warnings for X specifically:
   • twitter:card missing → X defaults to small summary
   • Image exceeds 5 MB → X refuses to render
   • Image ratio far from 2:1 → X crops or letterboxes
   • Relative image URL → crawler cannot resolve

The same check also renders your card for Facebook, LinkedIn, WhatsApp, Discord, Slack, Telegram and Reddit — so one validation covers every platform your link might end up on.

What happened to the old Twitter Card Validator?

The original validator lived at cards-dev.twitter.com/validator. It was a simple tool: paste a URL, see your card, force a refresh. When Twitter became X in 2023, the tool was eventually retired.

X now offers a card preview inside its developer portal, but the path to it is not obvious:

• You need an X Developer account (requires application approval)
• Navigate to the Cards Tester tool in the portal
• Paste your URL and view the rendered card
• There is no batch testing, no other-platform previews, no tag-level audit

For anyone who just wants a free Twitter Card validator — something online that works in five seconds without a developer account — that is too much friction. Our validator was built for exactly that gap — the five-second answer to “does my card look right?”

What the validator checks (tag by tag)

Here is the full audit the tool runs against your twitter meta tags, specifically for X:

Tag	What it checks	Why it matters for X
twitter:card	Present, set to summary_large_image	Without it, X renders the small summary format
twitter:title	Present, ≤70 characters	X truncates long titles; falls back to og:title
twitter:description	Present, ≤200 characters	Falls back to og:description
twitter:image	Absolute https:// URL, valid image, ≥300×157 and ≤4096×4096 px	Falls back to og:image; must be under 5 MB
og:title	Present, ≤60 characters	X fallback when twitter:title absent
og:description	Present, ≤200 characters	X fallback
og:image	Absolute URL, loads, dimensions correct	X fallback; checked for real file size and aspect ratio
og:url	Present, absolute	Helps platforms consolidate share counts

The audit also loads your actual og:image file — not just checks the tag — and measures its pixel dimensions, file size in bytes, and format. This catches the “the tag is there but the image is 4 MB PNG” problem that breaks X and especially WhatsApp.

For a closer look at open graph vs twitter card — which platforms read which tags, and when you need both — see What Is Open Graph?.

Free Twitter Card preview tools compared

If you are looking for a Twitter Card validator alternative now that the original is gone, here is the honest landscape:

Tool	X card preview	Other platforms	Tag audit	Account needed
ogimagechecker.com	✅	✅ 8 platforms	✅ pass/warn/fail + score	❌
X Developer Portal	✅	❌	Basic	✅ developer account
Facebook Sharing Debugger	❌	Facebook only	✅ (FB-specific)	✅ Facebook account
LinkedIn Post Inspector	❌	LinkedIn only	✅ (LinkedIn-specific)	❌

The X developer portal remains the only place to force X to re-crawl a stale card (it has a “refresh” action). For everything else — validating before you post, checking across platforms, auditing tags — the tool above covers it in one pass.

How to fix what the validator finds

Missing twitter:card? Add one line to your <head>:

<meta name="twitter:card" content="summary_large_image" />

X will pull everything else from your OG tags. See Twitter Cards: The Complete Guide for the full tag set.

Image missing or wrong size? Building your first side project and need a card image fast? The OG Image Generator — it has a 1200×600 preset (X’s native 2:1 ratio) and exports as JPG (typically 50–150 KB, well under the 5 MB limit). Pick a template, type your title, download. If you want to see a twitter card example done right, browse our examples gallery — 26 real brands rendered as live cards.

Tags rendered by JavaScript? Move them to server-side rendering, or use your framework’s meta management (Next.js metadata, Astro <head>, Nuxt useHead). For a full audit of every tag on the page, not just OG/Twitter, run the Meta Tag Checker.

Stale cache? Share a new post on X (not a retweet of the old one). If you have a developer account, use the portal’s Card Tester to force a re-crawl.

How to test your card before every publish (the workflow)

If you want to validate a Twitter Card before every post — or run a quick twitter card test as part of your publishing workflow — here is the three-step routine that catches problems before your audience does:

1. After deploying a new page, paste the URL into the OG Image Checker — this is your pre-flight check.
2. Confirm the X card renders correctly (image, title, description, domain).
3. If anything is flagged, fix the tags, redeploy, re-check. The checker fetches fresh every time — no stale cache.
4. Once the card passes, share the link with confidence.

For automated checking, the free API runs the same audit programmatically. Gate your CI pipeline: if the OG score drops below 70, the build fails — broken previews never reach production.

FAQ

Is there an official Twitter Card validator?

X retired the original Card Validator at cards-dev.twitter.com/validator. The developer portal has a Card Tester, but it requires an approved developer account. The free validator at ogimagechecker.com renders your X card without any account or key.

How do I validate my Twitter Card?

Paste your live URL into the OG Image Checker — it fetches the page, reads every twitter:* and og:* tag, renders the X preview card, and flags errors. Takes about ten seconds.

What is twitter:card validation?

Checking that your page’s meta tags are correct enough for X to render a rich preview. The most common failure: a missing twitter:card tag, which causes X to show a small thumbnail instead of your full-width image.

Why is my Twitter Card not showing?

Check five things: twitter:card tag present, og:image present with an absolute URL, image under 5 MB, tags in server-rendered HTML (not JavaScript-injected), and stale cache (share a new post, not a retweet).

Do I need twitter:* tags if I have Open Graph tags?

Only twitter:card is required. X falls back to your og:title, og:description and og:image for everything else. Add twitter:* overrides only when you want X-specific values.