Skip to content
SeenLens

Schema checker

The schema checker reads the JSON-LD structured data on a page and reports syntax errors, schema.org types and common missing properties. It fetches the page HTML once and checks every application/ld+json block. The result shows whether machines can read your markup. It does not decide rich result eligibility. Google's Rich Results Test decides that.

By SeenLens · Last updated

Free, no sign-up. We fetch the page HTML once, as SeenLensBot, and read its JSON-LD. We do not store the page.

What does the schema checker test?

Enter a page URL. The checker requests the page once as SeenLensBot (SeenLensBot/0.1 (+https://seenlens.com/bot)) and reads the HTML that comes back. It follows the robots.txt rules for SeenLensBot. See the SeenLensBot page for details.

What the schema checker reports
TestResult
JSON syntaxEvery <script type="application/ld+json"> block on the page, with a parse error for each block that fails.
Schema.org typesAll types found, including the members of an @graph.
Entity markupWhether Organization or WebSite markup exists.
Missing propertiesCommon gaps per type. Organization: name, url, logo. Article: headline, author, datePublished. Product: name, offers.
Other formatsA note when the page also uses Microdata or RDFa.

The checker reads the HTML response of one request. If a script adds the JSON-LD after the page loads, that markup is not in the response and the checker does not see it.

How is it different from the Rich Results Test and the Schema Markup Validator?

Three tools read structured data, and each answers a different question. Google says the Schema Markup Validator does not check Google Search rich result types. For those, Google points to the Rich Results Test.

Structured data tools and when to use each
ToolQuestion it answersUse it when
SeenLens schema checkerDoes the page have JSON-LD, does every block parse, and are common properties missing?You want a fast check next to crawler access, content structure and the other AI readiness checks.
Google Rich Results TestCan this page produce Google rich results? It takes a public URL or pasted code.You want rich result eligibility in Google Search. Use it instead of the SeenLens checker for that question.
Schema Markup ValidatorDoes the markup follow schema.org? Google's 2020 announcement says its main purpose is to check syntax and compliance with schema.org standards.You use types that Google does not support for rich results, or you want a check against the full schema.org vocabulary.

How do I read the result?

  • Every block parses and the types match the page. The markup is readable. Check that each type describes content that is visible on the page.
  • A block fails to parse. A parser cannot read a block with a JSON syntax error, so the facts in it are lost. Fix the syntax first. See JSON-LD syntax errors.
  • No JSON-LD found. The HTML response has no application/ld+json block. Check that the server sends the script in the HTML and that you entered the right URL. See add JSON-LD.
  • No Organization or WebSite markup. Engines cannot read who runs the site from structured data. See add Organization schema.
  • Missing properties. These are hints, not errors. Add a property only when the page shows that fact. Required properties differ by rich result type, so use the Rich Results Test for Google's list.
  • Microdata or RDFa noted. The checker found another format. Google recommends JSON-LD when your site setup allows it.

How do I fix schema errors?

After you publish the change, run the schema checker again. Then run the Rich Results Test if you want Google rich results.

Frequently asked questions

Is the SeenLens schema checker the same as the Rich Results Test?

No. The Rich Results Test decides whether a page can produce Google rich results. The SeenLens checker reads JSON-LD and reports syntax errors, types and common missing properties. Use the Rich Results Test for rich result eligibility.

Why does the checker find no JSON-LD when I added it?

The checker reads the HTML from one request. A script that adds JSON-LD after the page loads does not appear in that HTML. Also check that robots.txt does not block SeenLensBot and that you entered the correct URL.

Does schema markup get my page cited by ChatGPT or Google AI Overviews?

No proven link exists. Google says no special schema.org markup is needed for its AI features, and the Ahrefs study of 2026-05-11 found no significant citation lift. Structured data still serves rich results and entity clarity.

Sources