Google announced it has made several updates to the Structured Data Testing Tool today. With that, the company updated its documentation and guidelines around structured data and markup and also began supporting JSON-LD markup syntax.
The new structured data testing tool added these features:
Validation for all Google features powered by structured dataSupport for markup in the JSON-LD syntax, including in dynamic HTML pagesClean display of the structured data items on your pageSyntax highlighting of markup problems right in your HTML source code
Here is a picture of the new interface:
The new tool should make it faster and easier for developers to understand and use.