Schema.dev

Schema.dev is a free set of structured data tools from seoClarity Labs, part of the enterprise SEO platform seoClarity, which has worked with SEO teams since 2008. The work splits into three steps. A point and click Schema Builder, delivered as a Chrome extension, walks a person through defining Schema.org markup for many schema types and lets them enter custom text for any field. A Schema Tester checks the markup and reports errors, warnings and recommended elements, and an API lets that testing run at scale across many pages. A Schema Deployer then publishes the finished markup so it does not wait on a development queue. A blog follows new structured data developments, such as the regionsAllowed property on VideoObject, and a roadmap shows what is planned. All of the tools are free.