Schema markup checker

What is a Schema Markup Checker?

The Schema Markup Checker scans a webpage for JSON-LD structured data (schema.org markup) and validates that each block is syntactically valid JSON, which is the format required for it to be usable by search engines.

Why Structured Data Matters

• Rich results — Valid schema markup (Product, Article, FAQ, Review, etc.) is what enables star ratings, prices, and other rich snippets in search results.
• Machine readability — Structured data explicitly tells search engines and AI crawlers what an entity on the page represents, reducing ambiguity.
• Invalid JSON is ignored — Even a single syntax error in a JSON-LD block can cause the entire schema to be silently discarded by parsers.