What is JSON-LD?

JSON-LD (JavaScript Object Notation for Linked Data) is the format search engines recommend for structured data. A page adds a <script type="application/ld+json"> block that describes what the page is about, such as a product with its price, an article with its author, or an organization with its logo, using types and properties from the schema.org vocabulary. Google, Bing, and other search engines read these blocks to show rich results like star ratings, prices, breadcrumbs, and recipe cards.

Mistakes in JSON-LD fail silently. The page still loads, but a missing comma, a misspelled type, or a missing required field means search engines ignore the markup or the page loses its rich result.

Tool description

This tool fetches a page's HTML on the server, finds every JSON-LD script block, and checks each one in two steps. First it checks the JSON-LD itself: that the JSON parses, that each item has an @context pointing at schema.org and an @type, and that keywords such as @type and @id are spelled and shaped correctly. Then it checks the content against the schema.org vocabulary and Google's rich result rules, reporting unknown types, properties that don't belong to a type, and required or recommended fields that are missing or have the wrong format.

Features

  • Finds every JSON-LD block on a live page, in <head> or <body>
  • Reports JSON syntax errors with the parser's message
  • Checks @context, @type, @id, @graph, and keyword spelling
  • Flags unknown schema.org types and properties that a type doesn't support
  • Checks Google's required and recommended fields for products, offers, reviews, ratings, recipes, job postings, videos, breadcrumbs, and more
  • Lists every structured data item with its type and name
  • Shows each block as formatted JSON

How it works

The page is downloaded without following redirects, and at most its first 3 MB are read. Each JSON-LD block is parsed separately, and items inside an @graph are checked as separate items. The schema.org checks use a copy of the full schema.org vocabulary, and the Google rich result checks use Adobe's open source structured data validator.

Tips

  • Errors mean search engines are likely to ignore the item or it won't get a rich result, so fix them first. Warnings are usually recommended fields, and adding them can improve how the result looks.
  • JSON-LD keywords are case-sensitive: @type works, @Type does not.
  • Use absolute URLs for url, image, and logo, and ISO 8601 dates such as 2026-09-25 or 2026-09-25T10:00:00+02:00.
  • The tool reads the HTML the server returns. JSON-LD added later by JavaScript in the browser won't be found.