Best API Design & Documentation Platforms

API design and documentation platforms offer tools for modeling endpoints, defining data schemas, and generating interactive developer documentation. They support industry standards including OpenAPI, RAML, and GraphQL SDL, aiding collaboration between developers, designers, and product teams. Included are web-based visual editors, hosted documentation portals, and specification management systems; excluded are API testing clients, gateways, and general-purpose static site generators. Primary considerations include standards compliance, multi-user collaboration support, and integration with development workflows.