Postman

Postman is a platform for building, testing, documenting and collaborating on APIs. It started as a simple tool for sending HTTP requests and inspecting responses, and grew into one of the most widely used developer tools in the world, used by millions of developers and most large companies. Its origin explains its popularity. Testing an API from the command line or writing throwaway code is tedious; Postman provided a friendly interface where developers could construct requests, set headers and authentication, send them and read formatted responses. Saving requests into collections, with variables and environments for different stages such as development and production, made it easy to reuse and share API calls across a team. The platform now covers the API lifecycle. Developers can design APIs using specifications such as OpenAPI, generate documentation automatically, create mock servers so front-end teams can work before the backend is ready, and write automated tests that run in continuous integration pipelines through the Newman runner and Postman CLI. Monitors check API health on a schedule, and workspaces let teams and external partners collaborate on collections. The Public API Network hosts collections from many companies, making it easier to start using their APIs. Postman supports REST, GraphQL, gRPC and WebSocket, and AI features help write tests, generate requests and build AI agents that call APIs. Postman offers a free plan for individuals and small teams, with paid plans adding collaboration, governance and enterprise features. Common criticisms are that the app has grown heavy compared with its original simplicity, and that pushing users toward cloud accounts and syncing concerns some developers who prefer local-only tools. Alternatives include Insomnia, a lighter API client from Kong; Bruno, an open-source client that stores collections as files in Git; Hoppscotch, open source and web-based; Thunder Client inside VS Code; Paw (RapidAPI) for Mac; Stoplight for API design; and curl or HTTPie for the command line. Choose Postman when you want a full-featured, collaborative platform for working with APIs across a team.