Structured Data Markup Visualization, Validation and Testing Tools
Tools for testing structured data markup and rich snippet display, including microformats and schema.org marked up in microdata, RDFa, RDFa Lite and JSON-LD.
When testing vocabularies and schemas, note that error messages from validators may be related to the usage requirements of only that specific data consumer, especially validation error pertaining to required fields or required properties.
Main Multi-Format Validators
Google Structured Data Testing Tool
Google's tool for validating schema.org, microformats and other structured data. Handles HTML marked up with microdata, RDFa, RDFa Lite and JSON-LD, by direct input or by fetching an existing URL. Includes examples for a range of entity types, including logos, corporate contacts, social profile links, Knowledge Graph events, actions, reviews, breadcrumbs and sitelink search boxes.
Yandex Structured Data Validator API
API that automates validation of semantic markup. Supports validation of JSON-LD, RDFa, microdata and microformats. Post-validation the API outputs the structured data extracted from a page in JSON format, or optionally reports only validation errors.
Structured Data Linter
Validation and visualization tool for microdata, JSON-LD and RDFa, along with vocabulary validation support for schema.org, FOAF, SIOC, SKOS and Dublin Core (DCMI).
Bing Markup Validator
Bing Webmaster Tools
Use of this tool requires you first to login to Bing Webmaster Tools. Supports only URL validation, not validation by direct input. Note that once logged in a webmaster can use the Validator to check the markup of any URL, not just the URLs of domains belonging to that Webmaster Tools account.
Open Graph Tools
Google Validators for Specific Item Types
Email Markup Tester
Google Developers/Google Webmaster Tools
Validator for JSON-LD and microdata, providing properties for each entity and specific error messages for invalid input.
Matthis de Wit
"This extension lets you know if there is Microdata or JSON-LD on a website an shows it to you."
Structured Data Conversion Tools and Utilities
Alex Stolz / Martin Hepp / Bene Rodriguez-Castro
A multi-format conversion tool for structured markup, providing conversions to and from RDFa, microdata, JSON-LD, RDF/XML, RDF/JSON and more. Conversion input can be a URI or text. Comes with a REST API for developers.
Testing Tool Graveyard
Google Structured Data Testing Tool
Google Webmaster Tools
The original Google tool (previously known as the Rich Snippet Testing Tool for validating schema.org, microformats and other structured data, and for generating previews of rich snippets in Google search results for supported types. Handled HTML marked up with microdata, RDFa and RDFa Lite. Redirected to the new tool February 2015.
Sindice Web Data Inspector
The Inspector was a structured data visualization and validation tool for RDF files, HTML pages embedding microformats and XHTML pages embedding RDFa. The founding team announced the end of support for sindice.com in May 2014.
Corporate Contacts Markup Tester
Google's tool for validating schema.org/Organization and schema.org/ContactPoint markup, with JSON-LD support. Seemingly rolled into the main Structured Data Testing Tool, to which it was redirecting until the address of the Tools changed.
Event Markup Tester
Google's tool for validating schema.org/Event markup, with JSON-LD support. Seemingly rolled into the main Structured Data Testing Tool, to which it was redirecting until the address of the Tools changed.
Last updated 30 December 2015