Validate structured data

Reference

Validation confirms that your markup parses correctly and uses the vocabulary as intended. Validate before you publish and again after any content change.

Objective

Catch syntax errors, wrong property names, and type mismatches before they reach production.

Steps

1. Parse the markup. For JSON-LD, confirm the block is valid JSON. A single trailing comma or unquoted key will break the entire block.

2. Confirm the type exists. The value of @type, itemtype, or typeof must be a real schema.org type. A misspelled type name means the item is ignored.

3. Confirm property names. Each property must be defined on the chosen type or one of its ancestors. Unknown property names are dropped.

4. Confirm expected value types. A property that expects a Date should receive an ISO 8601 date. A property that expects a nested entity should receive an object with its own type, not a plain string.

5. Check enumerations. Properties such as availability expect an enumeration member written as a full vocabulary identifier, for example https://schema.org/InStock.

6. Confirm visible content alignment. The structured data must describe what a user actually sees on the page.

7. Re validate after changes. Templates and content management systems can silently change output. Re run validation after deploys.

A minimal checklist

• The block parses with no syntax errors.
• The type is spelled correctly and is the most specific accurate type.
• Required properties are present.
• Dates use ISO 8601.
• Currency and price values are strings.
• Enumeration values use full vocabulary identifiers.
• Structured data matches visible content.

Done when

• The validator reports zero errors for the chosen type.
• Warnings have been reviewed and either resolved or accepted with a documented reason.