This free schema validator checks your JSON-LD structured data for syntax errors and, for the most common schema types, flags the recommended fields Google and AI engines look for but you have not included. Paste your markup and get a plain-English pass, warning, or error list for every block. No signup, nothing leaves your browser.
How to use the schema validator
- Copy the JSON-LD from inside your
<script type="application/ld+json">tag — everything between the braces. - Paste it into the box and press Validate. Nested
@grapharrays and multiple blocks are all checked. - Read the per-block results: a green tick means the recommended field is present, an amber flag means it is missing, and a red cross means a structural error that will stop the markup being read.
- Fix the flagged fields in your source, re-paste, and re-validate until every block reads green.
Valid schema is how you earn rich results and AI citations
Structured data tells search engines and AI systems exactly what a page is — an article, an FAQ, a product, an organization — so they can display rich results and quote you with confidence. But malformed or incomplete JSON-LD is worse than none: a single syntax error can make an engine skip the whole block. This tool catches the two failure modes that matter most — invalid JSON, and missing recommended fields for common types. It pairs naturally with the Schema Markup Generator (which builds the markup) and the FAQ Schema Generator. To understand why this feeds AI visibility, see how AI citation systems work.
Related tools and guides
- Schema Markup Generator — build valid JSON-LD for common types.
- FAQ Schema Generator — turn Q&A into FAQPage markup.
- AEO Readiness Analyzer — score a full page for AI extractability.
- Structured Data for AI Search — which schema types matter most.
Frequently Asked Questions
Does this replace Google’s Rich Results Test?
No — it complements it. Google’s Rich Results Test and the Schema.org validator check eligibility against Google’s live rules. This tool runs entirely in your browser for a fast first pass: it catches invalid JSON and missing recommended fields before you paste anything into an external validator, which saves round-trips while you are drafting.
What schema types does it check recommended fields for?
It has field checklists for the most common types: Article, NewsArticle, BlogPosting, FAQPage, BreadcrumbList, Organization, LocalBusiness, Product, Offer, SoftwareApplication, HowTo, Recipe, Event, Person, VideoObject, WebSite, Review, Course, JobPosting, ItemList and CollectionPage. Any other valid schema.org type is recognised but not field-checked — verify those against schema.org directly.
Can it handle @graph and multiple blocks?
Yes. It walks the whole structure — a single object, an array of objects, or an @graph node containing many entities — and reports on every typed node it finds, so pages that combine Organization, WebSite, Article and BreadcrumbList in one graph are all covered.
Why is a warning not an error?
An error (red) means the markup is structurally broken — invalid JSON, or an FAQ question with no answer — and engines will likely ignore it. A warning (amber) means the JSON is valid but a field Google recommends is absent; the markup still works, but adding the field improves your chances of a rich result.
Is this tool free and private?
Yes — completely free, no account, and everything runs in your browser, so nothing you paste is sent to a server. It is part of the free Plain Intelligence resource hub.
Want your structured data audited across the whole site? See our technical SEO service, or browse all free tools in the resource hub.