Schema Entities Auditor

Schema.org is the shared vocabulary that search engines, social networks and AI answer engines use to understand a page: whether it is an article, a product, an organization, an event or a recipe, and which properties describe it. The vocabulary can be embedded as JSON-LD (<script type="application/ld+json">, the format Google recommends), as Microdata (itemscope / itemtype attributes on HTML elements) or as RDFa (vocab / typeof attributes). This auditor fetches the page once and counts the entities it finds in each format.

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How it works

1. Fetch — sends a GET request to the audited URL as 37AuditsBot with an Accept header that prefers HTML. A blocked request ends the audit with 590; any other failure (timeout, DNS, TLS, non-2xx answer) ends it with 500.
2. JSON-LD — parses every <script type="application/ld+json"> block. Each object with a @type counts as one entity when its @context names schema.org, its type uses the schema: prefix or is a bare type name; objects nested under @graph are counted too. A block that does not parse as JSON is skipped when counting and recorded for the 300 rule.
3. Microdata — every element with itemscope and an itemtype under schema.org counts once per type IRI.
4. RDFa — every element with typeof counts once per type when it or an ancestor declares vocab under schema.org, or when the type uses the schema: prefix.
5. Rules — no entity in any format fails (400); each malformed JSON-LD block warns (300).
6. Aggregate — FAIL wins over WARNING; when every rule passes the audit is SUCCESS (200) and the message lists the counts per format and per type.

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What it audits

Every row maps to one checkRule* method and one CheckCode, in the order the auditor runs them. CheckCode suffixes use status ranges: 200 success, 300–399 warning, 400–499 fail, 500–599 error.

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Output documentation

Every check carries the same data map: totalEntities, byFormat (jsonLd, microdata, rdfa counts), types (count per type name), examples (up to five snippets of the entities found, omitted when there are none) and malformedJsonLdBlocks (block ordinal and parser error for each JSON-LD block that failed to parse).

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Risks and considerations

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Why structured data matters

• Rich results (star ratings, prices, FAQ drop-downs, breadcrumbs, event dates) only appear for pages that describe themselves with Schema.org entities; they take more space on the results page and earn more clicks than a plain listing.
• AI answer engines and search assistants rely on the same entities to tell an article from a product page, to name the publisher and to cite the page with confidence.

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JSON-LD first

• Google recommends JSON-LD: it lives in one <script> block, does not depend on the HTML layout and survives redesigns. Microdata and RDFa still count, but they break more easily when templates change.
• A single typo (a trailing comma, an unescaped quote, a truncated block) makes the whole block unreadable. Validate it after every template change with the Schema.org validator or Google’s Rich Results Test.

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What this auditor does not check

• Only the audited URL is fetched; other pages of the site may carry different or no structured data.
• The auditor counts entities and parse failures. It does not validate that the properties of an entity are the ones its type requires, nor that the values are correct, so a page can pass here and still not qualify for rich results.
• Structured data injected by JavaScript after the page loads is not seen: the auditor reads the HTML as served.
• Types from vocabularies other than Schema.org are ignored.