Tools for Testing Structured Data Markup

Structured data is easy to add and equally easy to get subtly wrong. A missing property, an unexpected value type, or markup attached to the wrong element may still look perfectly normal in the browser.

I collected these tools for checking Schema.org markup and the formats commonly used to publish it: JSON-LD, Microdata, RDFa, and RDFa Lite.

Validators and previews

• Google Structured Data Testing Tool accepts a URL or pasted markup and shows the structured data it can extract.
• Yandex Structured Data Validator checks formats including Schema.org, Microdata, microformats, Open Graph, and RDF.
• Bing Markup Validator validates Microdata, microformats, RDFa, and Schema.org markup.
• RDFa Playground previews data extracted from HTML and RDFa, with a raw-data view for closer inspection.
• Facebook Sharing Debugger shows the information Facebook and Messenger use when a page is shared. Its batch tool can refresh multiple URLs.
• Google Email Markup Tester checks Schema.org markup intended for email.
• Structured Data Linter extracts and checks Microdata, JSON-LD, and RDFa from HTML pages.
• Structured Data Testing Tool extension brings Google’s testing tool into a Chrome extension.

Playgrounds, parsers, and converters

• JSON-LD Playground lets you edit JSON-LD and inspect the expanded or transformed output.
• RDF Translator converts between formats including RDF/XML, RDFa, and Microdata. It accepts a URL or pasted text and also provides an API.
• Microdata Tool is a jQuery script that can inspect Microdata locally, even without a web server.
• Mida is a Microdata parser and extractor for Ruby.
• RDFa-Lab Bookmarklets provide bookmark-based tools that run against the current page.
• Schema.org Visualizer turns Schema.org data into a visual representation.

Markup generators

• Google Structured Data Markup Helper helps annotate a sample page and generate structured markup.
• Microdata Generator generates Schema.org Microdata.
• Web Code Tools generates HTML, CSS, Microdata, Twitter Card, and Open Graph markup.
• MicrodataGenerator.org is another focused Schema.org Microdata generator.
• JSON-LD Site Name Generator creates JSON-LD for a site’s name.
• JSON-LD Schema Generator for SEO generates JSON-LD for several common page types.

A validator can confirm that markup is readable, but it cannot guarantee a special search result. I would use at least the validator from the search engine I care about, then inspect the page again after it has been crawled.