The best free schema markup validators, ranked
By Philipp Kant 4 min read
A schema markup validator is a tool that reads the structured data on a page, usually JSON-LD using the schema.org vocabulary, and reports syntax errors, unknown types, and missing properties. Free validators split into two groups: Google’s tools, which test eligibility for Google’s rich results, and generic validators, which test schema.org correctness.
The split explains most confusion. Markup can be valid schema.org and still produce no rich result, because Google applies its own rules on top. And it can pass Google’s test while describing the business poorly to everyone else.
| Tool | Tests | Scope | Free tier |
|---|---|---|---|
| Rich Results Test | Google rich result eligibility | One URL or snippet | Free, no signup |
| Schema Markup Validator | All schema.org types | One URL or snippet | Free, no signup |
| Search Console reports | Rich result errors from real crawls | Whole site | Free, verified site |
| JSON-LD Playground | JSON-LD processing | Code snippet | Free, no signup |
1. Rich Results Test, Google’s own verdict
Google’s Rich Results Test answers one question: which Google rich results can this page get. It fetches the page with Googlebot, renders it, and lists the detected items, with errors that block a rich result and warnings that only weaken it. It also previews the result.
It knows only the types Google supports. An Organization graph with
sameAs links, which matters for how search engines and AI assistants
identify a business, gets little attention here.
2. Schema Markup Validator, the full vocabulary
The Schema Markup Validator at validator.schema.org is the successor of Google’s old Structured Data Testing Tool, handed over to schema.org in 2021. It validates every schema.org type and property, with no Google feature rules mixed in, and shows the parsed graph as a tree.
Use it for everything Google’s test ignores: entity markup, nested relationships, and types without a rich result.
3. Search Console, the site-wide picture
Search Console’s rich result reports list every page with detected markup by type, with errors grouped and a trend over time. It is the only free tool here that covers the whole site from real crawls, and the place to confirm a fix with “Validate fix”.
It needs a verified property, it lags days behind changes, and it reports only the types Google uses.
4. JSON-LD Playground, for debugging the graph
The JSON-LD Playground shows how a JSON-LD processor reads your markup:
expanded, compacted, flattened. That sounds academic until two blocks on a
page describe the same organization with different @id values, and the
graph silently becomes two organizations.
It is a developer tool. It checks JSON-LD processing, not schema.org semantics or Google rules.
What Google still rewards
Google has narrowed its rich results over the years. Since 2023, FAQ rich results appear only for well-known government and health sites, and HowTo results are gone. In 2025 several more types were retired. What remains worth the effort for most businesses:
| Type | Where it shows |
|---|---|
Product with Offer |
Price, availability, ratings in results and Shopping |
Organization / LocalBusiness |
Logo, contact details, knowledge panel signals |
Article / BlogPosting |
Dates and authorship |
BreadcrumbList |
The path shown instead of the raw URL |
Event, Recipe, JobPosting |
Their own rich layouts |
What valid markup still misses
A validator confirms syntax. It does not confirm that the markup does its job:
- Markup injected by JavaScript. Google renders and finds it. AI crawlers read the raw HTML and do not; see can AI crawlers read JavaScript?
- A thin entity. An
Organizationwithoutlogo,address, orsameAslinks to the company’s profiles is valid and says almost nothing. - Contradictions. A price in the markup that differs from the price on the page is valid JSON-LD and a reason for Google to ignore it.
- Several graphs, no connection. Plugins often add their own blocks.
Without shared
@idvalues, the organization, the website, and the page never link up.
FAQ
What is the best free schema markup validator? Use two: the Rich Results Test for Google eligibility and the Schema Markup Validator for schema.org correctness. Add Search Console for the whole site.
Why does valid markup not show rich results? Valid is not eligible. Google applies its own required properties, quality rules, and type restrictions, and shows rich results at its discretion even when everything passes.
Does schema markup help with AI search? It makes facts unambiguous: who the business is, which profiles belong to it, what a product costs. That helps systems resolve the entity. It does not make a page rank or get cited on its own. Our AI visibility study of German websites shows how rare complete entity markup still is.
JSON-LD or Microdata? JSON-LD. Google recommends it, it sits in one block instead of being woven through the HTML, and it survives redesigns.
We built our own free Schema Markup Check
for the part validators skip: it reads every JSON-LD block on a page,
scores validity, types, and the completeness of the entity graph,
checks sameAs links, canonical, and social tags (for those, see
the best free Open Graph checkers),
and ranks the fixes.
Full disclosure, it is ours, and it needs no signup. If product data is
the source of the markup, the work starts upstream; see
product data for AI shopping, and
what we do when the catalog needs fixing at the root.
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