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Crawl diagnostics

Diagnosing structured data errors

Structured data (schema.org markup, usually as JSON-LD) lets search engines understand a page and can make it eligible for rich results. Errors — missing required properties, invalid types or values, markup that does not match visible content, or policy violations — can make a page ineligible for those features. Diagnosis uses validators and Search Console's rich-result reports.

Verified against primary sources

What structured data does

Structured data is machine-readable markup, recommended by Google as JSON-LD, that describes a page's content using schema.org types — for example Article, Product, FAQPage, or BreadcrumbList. When it is valid and matches the page, it can make the page eligible for rich results such as review stars, FAQs, or breadcrumbs.

Eligibility is the key word: correct markup is a prerequisite for a rich result, but it does not guarantee the feature will appear or improve rankings.

Common structured data errors

Frequent issues are missing required properties for the chosen type, using an invalid value or the wrong type, and markup that describes content not actually visible on the page — which violates Google's structured-data guidelines. Marking up content the user cannot see, or adding misleading markup, can make a page ineligible or trigger a manual action.

Other faults include malformed JSON-LD, referencing types Google does not support for rich results, and inconsistencies between the markup and the canonical page. Warnings (recommended-but-missing properties) are softer than errors but still worth addressing.

How to diagnose and fix

Test pages with Google's Rich Results Test and the Schema Markup Validator to see errors and warnings per item. In Search Console, the rich-result enhancement reports show errors aggregated across the site and let you validate fixes.

Resolve errors first (they block eligibility), then warnings (they improve completeness). Make sure the marked-up data reflects what is genuinely on the page, and re-test after changes so crawlers re-process the corrected markup.

How it appears in analytics and logs

Structured-data errors mean a page may not qualify for the rich result it targets. It is an eligibility signal, not a ranking guarantee: valid markup makes a page eligible, but search engines still decide whether to show the feature.

Diagnostic use case

Validate structured data against the required properties for the target rich-result type and fix errors so eligible pages can qualify for enhanced search features.

What WebmasterID can help detect

WebmasterID records which pages crawlers fetch and the status they return, helping you confirm that pages carrying structured data are reachable and returning 200 so the markup can be processed.

Common mistakes

Privacy and accuracy notes

Structured-data diagnosis uses page markup and crawler fetches, not visitor data. WebmasterID records crawler page fetches without attaching them to any person.

Frequently asked questions

Does valid structured data improve rankings?
Structured data can make a page eligible for rich results, but it is not a ranking factor on its own. Search engines still decide whether to show a rich result and how to rank the page.

Related pages

Sources and verification notes

Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.