Test the structured data on any page. Enter an address or paste HTML or JSON-LD to find broken JSON, missing required and recommended properties for Google's rich results, and values in the wrong format, such as dates, prices and relative image links.
The page is fetched once by Cromagnon's server, as a crawler would see it before scripts run. Markup added later by JavaScript (some plugins and tag managers) won't show; paste the rendered HTML from your browser's developer tools to check it.
Structured data only works when it is valid: one missing comma makes search engines ignore a whole script, and a missing required property stops a rich result from appearing. This validator reads the JSON-LD on a live page, or in HTML or JSON you paste, and checks every item in it. It reports broken JSON with the line and column, the properties Google requires and recommends for that type of rich result, and values written in a form search engines don't accept, such as a date like 27/10/2026, a price with a currency sign or an image path without https://.
Tip: Errors come first. A rich result needs every required property; recommended ones make it richer and more likely to show, but missing them never blocks it.
With a web address, Cromagnon's server fetches the page once, like a search engine crawler, and reads the HTML it receives. Redirects are followed and the final address is shown. Nothing is stored. Some sites block automated visitors and answer 403; for those, open the page in your browser, view the source, and paste it instead.
Markup that is added by JavaScript after the page loads, for example by some tag manager setups or app widgets, isn't in the first HTML, so it won't be found here. Google can render JavaScript and usually sees it eventually, but adding JSON-LD to the HTML itself is faster and more reliable. To check rendered markup, copy the page's HTML from your browser's developer tools (Elements panel, right-click <html>, Copy outer HTML) and paste it.
Google's Rich Results Test shows which rich results a page is eligible for, and the Schema Markup Validator at schema.org checks the vocabulary in general. This validator focuses on the mistakes that most often stop rich results, explains them in plain words, and works on pasted code before anything is published. Use it while you build, and use Google's test and Search Console's Enhancements reports to confirm after publishing.
Fix the template that outputs the markup and every product or post is fixed at once.
Valid markup that disagrees with the page (a different price or rating) can still lose rich results.
The Enhancements reports show errors across the whole site and when Google sees your fixes.
Several JSON-LD scripts on one page are fine; make sure they don't describe the same thing twice.
A double quote inside a text value must be written \", or the JSON breaks.
If the page uses itemscope attributes instead of JSON-LD, test it in Google's Rich Results Test.
Valid markup makes a page eligible, but Google decides whether to show a rich result based on the site's quality, the query and whether the markup matches the page. Some types (FAQ, How-to, self-serving reviews) are limited.
No, only JSON-LD, which is the format Google recommends. The tool tells you when a page uses Microdata or RDFa so you can test those in Google's Rich Results Test.
No. The server can only fetch public pages. Paste the HTML of a private page or a staging site instead.
Warnings are recommended properties. A rich result can appear without them, but they often make it more detailed or more likely to show.
No. A live page is fetched once and checked in your browser; pasted code never leaves your device. Nothing is stored or logged.
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