Technical SEO and sharing
Meta tag and Open Graph checker
Check the title, description, canonical, robots, hreflang and social card tags for any page. The previews show roughly how Google, Facebook, LinkedIn, X and WhatsApp will display it.
Runs on our edge server; we fetch the public page once and do not store it beyond a 10 minute cache.
Method
How it works
The checker reads the final HTML and extracts the title, the meta description, the canonical link, the robots directives from the meta tag and the X-Robots-Tag header, the hreflang alternates, and the Open Graph and X card tags.
Pixel widths use Arial character metrics. Titles are measured at 20px against about 580px, and descriptions at 13px against about 920px. Both figures are estimates, so use them to spot long copy rather than to set an exact limit.
The previews are drawn from the tags on the page. Images load from the address in og:image, so they are subject to the same availability as the image on your site.
FAQ
Questions people ask
Why does the checker estimate pixel widths?
Google does not publish its truncation rule. The checker estimates width with Arial character widths, using 20px for titles against about 580px and 13px for descriptions against about 920px. Treat the numbers as guidance, because the exact cut depends on the device and the characters used.
Which tags do Facebook, LinkedIn and WhatsApp use?
They read Open Graph tags, mainly og:title, og:description and og:image. Add og:image:width and og:image:height so platforms can reserve space. Use an absolute https:// image URL, because relative paths and plain http images may not display.
What does X use for its card?
X uses the twitter:card tag to choose the card type. summary_large_image gives the large preview, and the preview on this page follows that setting. Set twitter:title, twitter:description and twitter:image explicitly if you want to control them.
Should every page have a canonical link?
Yes, for pages that can be reached at more than one address, such as parameter URLs, trailing slash variants or print versions. The canonical should point to the address you want indexed, and it should match the final page URL.
What is an hreflang set?
It is a list of alternate language or region versions of the same page. Each page in the set should list itself and its alternates. The checker warns when a page is missing from its own set.
Does the checker fetch the og:image?
No. The previews load the image address from the page directly in your browser. The checker checks the address, the protocol and the reported size, and does not download the image itself.
Related tools
- Technical SEO & AI Search Schema Validator Validate JSON-LD against required and recommended properties for Organization, Article, Product, FAQPage, LocalBusiness and more.
- Technical SEO & AI Search Redirect Checker Follow every redirect hop, see status, Location and HSTS at each step, and flag loops, long chains and HTTPS downgrades.
- Technical SEO & AI Search robots.txt Generator Build a robots.txt with AI crawler controls, then test any file with the RFC 9309 longest-match rule.
Next step
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