Free toolTechnical AEO
Schema Markup Validator: Test Your Structured Data
Free tool by AEO GEO Labsby the AEO GEO Labs team4 min read
A schema markup validator checks that your structured data parses, uses real schema.org types, and has the properties search engines need. Three free tools cover the job: our structured data checker for the raw HTML that AI crawlers read, Google's Rich Results Test for Google eligibility, and validator.schema.org for general schema.org syntax. Use at least two.
Still deciding what markup to add? Start with our complete schema markup guide.
Which schema markup validator to use for what
Each validator answers a different question:
| Tool | Question it answers | Renders JavaScript? | Checks Google requirements? |
|---|---|---|---|
| Structured data checker | What does a non-rendering crawler see, and what's missing? | No, reads raw HTML | Required and recommended fields for common types |
| Google Rich Results Test | Is this page eligible for Google rich results? | Yes | Yes, for supported rich result types only |
| Schema Markup Validator | Is this valid schema.org, whatever the type? | Yes | No |
The Schema Markup Validator is the successor to Google's old Structured Data Testing Tool. Google moved that tool to schema.org in 2021 and refocused it on generic schema.org checks rather than Google features.
How to validate schema markup step by step
To validate schema markup properly, test the live URL in two views, raw and rendered:
- Run the raw HTML check. Paste your URL into the structured data checker. It parses every JSON-LD block, including nested nodes, and checks each against Google's required and recommended properties.
- Run the Rich Results Test. It renders the page as Googlebot, smartphone by default, and lists which rich result types are detected, with errors and warnings for each.
- Compare the two. If Google's test finds markup that our checker doesn't, your JSON-LD is injected by JavaScript. Google can see it; many AI crawlers can't.
- For types Google doesn't support, use validator.schema.org. Google's Rich Results Test help page notes it only reports on Google's supported rich result types. Anything else needs the schema.org validator.
- Re-test after every template change. Then watch Google Search Console's enhancement reports for new errors across the site.
How to read the results
Errors stop markup working; warnings reduce what it can do. What the structured data checker reports, and the fix:
| Result | Meaning | Fix |
|---|---|---|
| No structured data on this page | No JSON-LD, Microdata or RDFa in the HTML | Add markup, or move it out of a tag manager into the template |
| JSON-LD block won't parse | A syntax error, often a stray comma | Fix the JSON; engines skip the whole block |
| Required property missing | Not eligible for that rich result | Add each listed property |
| Recommended property missing | Eligible, but thinner | Fill the ones you have real data for |
| Value looks malformed | Bad date, relative URL or empty string | Use ISO 8601 dates and absolute URLs |
| sameAs doesn't link to Wikidata or Wikipedia | Weaker identity signal | Add those profiles if they exist |
What a valid result does not mean
Valid markup guarantees nothing in search. As of October 2026, Google says it doesn't guarantee structured data will show in results even when it's correct, and it no longer shows FAQ rich results for most sites. AI engines don't publish how they use schema at all. Validate to remove errors, then judge the markup by whether it describes your page truthfully. For what helps in AI answers specifically, read our guide to schema for AI search.
Frequently asked questions
What is the best free schema markup validator?
There isn't one best tool, because each checks something different. Google's Rich Results Test is the authority on Google rich result eligibility. validator.schema.org checks any schema.org type for syntax. Our structured data checker reads the raw HTML that non-rendering AI crawlers see. Use the Rich Results Test plus one of the others for full coverage.
What happened to Google's Structured Data Testing Tool?
Google retired it from Search and moved it to schema.org. In 2021 it became the Schema Markup Validator at validator.schema.org, focused on general schema.org syntax rather than Google features. For Google-specific checks, Google points people to the Rich Results Test.
Why does my schema pass in Google's test but not in other checkers?
Usually because JavaScript adds the markup after the page loads. Google's Rich Results Test renders JavaScript, so it sees the markup. Checkers that read raw HTML, and many AI crawlers, don't run JavaScript, so they see nothing. Move the JSON-LD into your server-rendered template so every crawler gets the same markup.
Do warnings in the Rich Results Test need fixing?
Warnings don't stop a page from being eligible for a rich result; errors do. A warning means a recommended property is missing, such as a review count or a product image. Fill them where you have accurate data, because each one gives machines more to work with. Never add invented values just to clear a warning.
How often should I validate structured data?
Validate whenever a template, plugin or CMS changes, since that is when markup breaks. Spot-check key page types monthly: homepage, a product or service page, and a blog post. Check Google Search Console's enhancement reports after each deploy for new errors across the site.
If you want this done for your site, AEO GEO Labs audits and fixes structured data as part of its GEO, AEO and SEO programs for B2B and SaaS teams. See our services.