Structured Data Validator

Paste HTML and check JSON-LD, microdata, and RDFa schema markup. See detected entities, properties, warnings, and errors — all locally in your browser.

Validate schema.org markup before you publish

Structured data helps search engines understand pages, products, recipes, articles, breadcrumbs, and organizations. This tool scans pasted HTML for the three common embedded formats — JSON-LD, microdata, and RDFa — and reports what it found.

What it checks

JSON-LD blocks in <script type="application/ld+json">.
Missing or non-schema.org @context values.
Objects that do not declare an @type.
Microdata itemscope, itemtype, and itemprop relationships.
itemprop attributes that are not inside any itemscope.
RDFa typeof / property blocks and missing vocabularies.

Output formats

Choose report for a readable summary with errors and warnings, or json for a machine-readable { counts, items, issues, valid } result that can be copied into tests or SEO QA notes.

Privacy

Everything runs locally in your browser through WebAssembly. Your HTML is not uploaded to a server.

FAQ

Is this the same as Google's Rich Results Test?

No. This is a fast local validator for common schema.org markup issues. Search-specific eligibility rules, live crawling, and Google-specific enhancements remain out of scope.

Can it validate malformed HTML?

The parser is browser-like and forgiving, so it can scan real-world fragments such as a copied `` section or a single product card.

Which structured data formats are supported?

JSON-LD, microdata, and RDFa. The report groups entities by format and lists detected types and properties.

Developer & Automation Access

Run it from the terminal

Same engine as this page, headless — via the gizza CLI:

gizza tool structured-data-validator '<script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"Hello"}</script>'

New to the CLI? Get gizza →

Open it by URL

Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:

https://gizza.ai/tools/structured-data-validator/?html=%3Cscript%20type%3D%22application%2Fld%2Bjson%22%3E%7B%22%40context%22%3A%22https%3A%2F%2Fschema.org%22%2C%22%40type%22%3A%22Article%22%2C%22headline%22%3A%22Hello%22%7D%3C%2Fscript%3E&format=report

Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.