Postman Echo vs US Extract

Postman Echo is a keyless sandbox that mirrors whatever you send it back as JSON — headers, query args, form body, cookies, and basic/digest auth attempts — across GET, POST, PUT, DELETE, and PATCH endpoints, plus helpers for testing redirects, delays, streaming, and gzip/deflate encoding. It's built and maintained by the Postman team as the reference backend for their own client tutorials and public collections, so its request/response shapes double as worked examples. There's no signup or key: every route is open, making it a quick target for scripting HTTP-client tests without standing up your own server.

Smarty's US Extract API scans arbitrary blocks of text — emails, PDFs-turned-text, scraped web pages, free-text form fields — to locate and validate US postal addresses embedded inside them, rather than requiring the caller to already know where an address starts and ends. Each match comes back with the same standardized, USPS-checked components (city, state, ZIP+4, delivery-point data) as Smarty's dedicated street-address API, plus the surrounding text offsets. It shares billing and account access with the rest of Smarty's address-data platform, so an existing Smarty key also works here.