Schema Markup Validator

A Schema Markup Validator checks structured data for machine-readable problems before you publish or troubleshoot a page. On this site, the validator focuses on JSON-LD because it is widely used and easier to inspect safely than trying to infer every possible microdata or RDFa relationship from arbitrary HTML. It checks JSON syntax, looks for linked-data fields such as `@context` and `@type`, and exposes the parsed structure so you can review what the markup actually says.

Structured data is easy to break with one missing comma, an incorrectly nested object or a field copied from an unrelated example. A page can render perfectly for users while its JSON-LD silently fails to parse. Validation catches those structural problems early, but it should not be confused with search-engine rich-result eligibility, which has additional product-specific requirements.

1. 1Copy the JSON-LD object from your page source or implementation code.
2. 2Paste the JSON-LD into the validator without the surrounding `<script>` tag if possible.
3. 3Run validation and resolve JSON syntax errors first.
4. 4Review detected `@context` and `@type` values to make sure they describe the visible page honestly.
5. 5After structural validation, use the relevant search-engine testing tool if your goal is a specific rich result.

• Valid JSON means the text is syntactically parseable; it does not mean every Schema.org property is semantically correct.
• A missing `@context` warning indicates the object may not clearly declare the vocabulary it uses.
• A detected `@type` tells you which entity the object claims to represent.
• Nested objects should mirror real relationships on the page rather than exist only because a sample template included them.

• Trailing commas copied from JavaScript objects into strict JSON.
• Smart quotes pasted from a rich-text editor.
• Using a schema type that does not match the page's main entity.
• Adding ratings, reviews, prices or authors that are not visible or real.
• Publishing duplicate JSON-LD blocks from both a plugin and custom code.

• Convert JavaScript-style objects into strict JSON before embedding them.
• Remove unsupported or fictional properties instead of filling them with placeholder values.
• Keep one authoritative source of structured data for each entity where possible.
• Validate after deployment because templates, escaping and minification can change the final output.

• Describe real entities and visible facts.
• Prefer the most specific appropriate Schema.org type without forcing an unrelated subtype.
• Use absolute URLs for important identifiers and page references.
• Treat structured data as a representation of the page, not a separate SEO story.

This validator checks syntax and basic linked-data structure. It does not guarantee that Google, Bing or another platform will use the markup, and it does not replace product-specific rich result documentation.