Today we are releasing SDO-Check, our semantic data testing tool!

Screenshot of SDO-Check

SDO-Check is a free-to-use web-tool that enables the fast and simple verification of annotations. This latest addition to the toolkit allows the input of a code-snippet or a web-page URL and shows the verification result in form of an interactive tree-visualization with details about all irregularities found. The verification is based on the latest version of the official vocabulary, common SEO practices, and recommendations from semantic web experts.


   ∗ All markup formats of are supported (JSON-LD, RDFa, Microdata).

   ∗ Allows input of code-snippets (HTML and JSON-LD).

   ∗ Allows input of web-page URLs (also handles dynamically loaded structured data markup).

   ∗ Fully aligned with, since the verification happens dynamically with official vocabulary files.

   ∗ Three different error severities (Warning, Error, Critical Error).

   ∗ Visualization and detailed explanation of found errors.


tree-visualization of SDO-Check

Input annotation as tree-visualization with error highlighting

Error detail view of SDO-Check

Details about the selected error, including an explanation of the issue, vocabulary-related context, and a dynamically generated example.


Although SDO-Check will continue to adopt more and more features, formats, and technologies that are related to, the tool focuses on those common patterns used in annotations on web-pages. Right now SDO-Check assumes that the only vocabulary used in the input annotation is and that a simple @context is used (in JSON-LD there could be unlimited variations, but we focus on the most readable, shortest and common used versions). There are some parts of the JSON-LD specification that are not fully supported yet, e.g. the use of @reverse, @graph, or typed values.

Future work

SDO-Check is actively being improved, you will find the newest changes in our changelog.

If you have questions or feedback regarding this tool, you can contact us on Twitter or via email!


Try it out!