Structured Data Testing Tool (SDTT)

SDTT v4.5.0 is a library and CLI tool for inspecting and testing structured data on web pages, supporting JSON-LD, Microdata, and RDFa. It automatically detects Schema.org schemas in HTML or JSON sources, and includes built-in presets for Google, Twitter, Facebook, and social media meta tags. Users can create custom presets or schemas, and integrate with any test framework. The tool can accept URLs, files, strings, buffers, or streams, and output results to JSON. It is designed for ad-hoc testing or integration into CI/CD pipelines. Released under MIT license, it is actively maintained on GitHub.