JSON-LD validator: check Schema.org markup syntax + structure.
JSON-LD validation matters because Google silently ignores invalid markup. A missing comma, wrong @type, or required property gap means your structured data does nothing — but you have no way to know unless you validate. This tool catches syntax errors, validates against Schema.org canonical types, and warns about missing recommended properties.
About this tool.
Schema.org JSON-LD validation matters because Google silently ignores invalid markup. There is no rich-result penalty for broken JSON-LD — it simply does nothing. You can have a perfectly written structured-data block that contributes zero ranking value because of a missing comma or wrong property name.
This validator catches three classes of error: (1) JSON syntax errors (unparseable), (2) missing required Schema.org context or type declarations, (3) missing recommended properties for the most common Schema.org types. The recommended-property list is curated from Google's published Schema.org documentation and reflects 2026 best practices.
For full canonical validation, also run your markup through Google's Rich Results Test (search.google.com/test/rich-results) and Schema Markup Validator (validator.schema.org). Both are authoritative — this tool catches issues faster but is not a substitute for the official Google validator before launching production pages.
Common mistakes this catches: forgetting the @context declaration, using @type Organization without name or url, declaring LocalBusiness without geo coordinates, declaring FAQPage without mainEntity, declaring Person without sameAs (the E-E-A-T critical property for 2026 author entity recognition).
Why thin schema is worse than no schema: 2026 research from Whitehat SEO found that thin schema with only required fields produced a documented 18 percentage point citation penalty in Claude versus no schema at all. Lazy schema signals to LLMs that the page is auto-generated and untrustworthy. Full schema with recommended properties is required for ranking benefit.
ThatDeveloperGuy validates every Schema.org block on every page we build using a combination of this tool, Google's Rich Results Test, and the structured-data testing API integrated into our CI pipeline. We deliver zero broken schema in production, ever.
FAQ.
What's the difference between JSON-LD and Microdata?
JSON-LD is a separate script block in your page head. Microdata is inline attributes on existing HTML elements. Google explicitly prefers JSON-LD and recommends it as the default format for new implementations.
Why does my schema validate here but fail Google's Rich Results Test?
This tool checks syntax and recommended properties. Google's Rich Results Test checks against their own rich-result-specific requirements which are stricter. Always validate with both.
Can I have multiple JSON-LD blocks on one page?
Yes. Google parses every script tag with type application/ld+json and merges them. Multiple separate blocks are easier to maintain than one giant @graph.
What's @context and why does it matter?
@context tells the parser which vocabulary to use. For Schema.org, it should always be https://schema.org. Without it, the entire block is meaningless to Google and AI engines.
Does invalid JSON-LD hurt my SEO?
It doesn't penalize you, but it provides zero benefit. The investment in writing structured data is wasted unless it parses and validates.
How often should I re-validate my schema?
Quarterly minimum. Schema.org updates the specification regularly; Google updates rich-result requirements; new types emerge. Stale schema can lose rich-result eligibility silently.
Built by Joseph W. Anady at ThatDeveloperGuy. Need professional help? Get a free 48-hour audit.