Postman

Postman is the world's most widely adopted API platform, utilized by over 30 million developers to design, test, and manage web APIs. What originated as a lightweight browser extension has evolved into a comprehensive end-to-end platform that covers every phase of the API lifecycle, from initial specification design to automated regression testing and public documentation.

The platform features Postman AI Assistant (Postbot), an artificial intelligence companion that generates automated test scripts from natural language, drafts comprehensive documentation, fixes API call errors, and generates realistic mock data. Postman Collections allow engineering teams to organize requests, chain complex multi-step workflows, and execute automated regression test suites via the Newman command-line runner.

Postman is available as a desktop client for Windows, macOS, and Linux, as well as a full-featured web application. It offers a generous free tier for individual developers and small teams, with paid plans providing advanced workspace governance, team analytics, and extended mock server calls.