Twitter Card validator. Preview unboxed.
Paste your page HTML. Extracts every twitter:* meta tag, validates card type, title (≤70), description (≤200), and image dimensions. Falls back to OG tags where Twitter is missing — the same logic X actually uses.
Paste your page HTML. The tool extracts every <meta name="twitter:*"> tag, validates card type, lengths, and image presence. Falls back to OG tags where Twitter-specific tags are missing — the actual X parser logic.
Sources used by this validator
- X (Twitter) card spec
- Open Graph protocol — fallback chain when twitter:* is missing.
- summary_large_image gets ~2x engagement vs summary per X internal data.
Privacy: HTML parsed in-browser only.
Six questions users ask.
What card types does Twitter support?
Four types: summary (small square thumbnail, default), summary_large_image (banner — recommended for editorial), app (App Store linking), player (audio/video embed). summary_large_image gets ~2x engagement vs summary.
Will OG tags work if twitter:* is missing?
Yes — partially. X falls back to og:title, og:description, og:image when twitter:* are absent. The card type itself defaults to summary. Ship both OG and twitter:* tags.
What are the image size requirements?
summary_large_image: 300x157 minimum, 1200x628 recommended, 5MB max. summary: 144x144 minimum, 400x400 recommended.
Why isn't my card showing on X?
Three common causes. Cache: X caches metadata for 7 days. URL must be publicly accessible. Image must load via HTTPS.
Should twitter:site differ from twitter:creator?
Yes. twitter:site is the publisher's handle (brand). twitter:creator is the author's handle (person). Multi-author sites vary creator per article.
Does this tool log my HTML?
No. The form runs entirely in JavaScript on your device. Nothing is sent to Digital Heroes servers.
Three mistakes we see most.
X (the platform formerly known as Twitter) processes more than 200 million link previews a day, and roughly a third of them render as bare blue links because the publisher assumed Open Graph alone was enough. X's developer documentation on Cards states that X reads twitter:* tags first and falls back to OG only for a subset of fields.
Mistake 1, OG tags only, expecting X auto-fallback: teams ship og:title, og:description, og:image and call it done. X falls back to og:image, but not to og:title or og:description in many card types, and never sets twitter:card without an explicit declaration. X's summary_large_image documentation is explicit: ship twitter:card, twitter:title, twitter:description, and twitter:image as their own tags. Use OG as the universal layer and twitter:* as the X-specific override.
Mistake 2, missing twitter:image dimensions: X expects summary_large_image at 1200x628 with a 2MB ceiling, summary at 144x144 minimum (400x400 recommended). Shipping a 3MB PNG or a 600x315 image silently fails the card validation, with no UI warning until you check the X Card Validator. The tool on this page surfaces dimension and weight issues before X does. File-format also matters: JPG or PNG only; SVG and AVIF are rejected.
Mistake 3, wrong twitter:card type for the content: using summary (small square thumbnail) for a feature article that deserves summary_large_image, or summary_large_image for a tweet that only has a logo, both reduce click-through significantly. X internal data showed summary_large_image cards drove 60% more click-through than summary in 2018-era studies; the gap has narrowed but persists. Pick the card type based on whether you have a real editorial image; default to summary_large_image for blog posts, summary for product pages without a hero image.
When to actually use this: before publishing any new post, after editing OG or twitter:* tags in a template, when CTR on X drops without an obvious cause, and during quarterly social-audit sweeps. Our SEO service ships this check as part of every content-distribution audit.
Related Digital Heroes services + reading: See our SEO service for production-grade social-meta architecture, plus our Open Graph Preview and Meta Tag Generator. Sibling tools: SERP Preview Generator and Schema Markup Generator.
Link & navigation cluster.
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