Open source Postman alternatives

Postman is a leading API platform for building, testing, and collaborating on APIs, offering powerful tools to streamline API development and integration.

We’ve curated 8 top open-source alternatives to Postman, with bruno emerging as the best option based on our data, the tool is mainly built with JavaScript on the MIT license. Looking for open-source alternatives to Postman? Check out scalar and hoppscotch.

  1. bruno icon

    #1bruno

    A revolutionary offline-first API client that stores collections directly on your filesystem using the Bru markup language. Experience seamless API testing with Git integration for efficient team collaboration.

    28k•1k•JavaScript•MIT
    Screenshot of bruno website
  2. scalar icon

    #2scalar

    A modern, offline-first API client and documentation tool that seamlessly integrates with popular frameworks. This innovative solution transforms OpenAPI specifications into interactive references while offering robust request management capabilities.

    7k•253•TypeScript•MIT
    Screenshot of scalar website
  3. hoppscotch icon

    #3hoppscotch

    A powerful open-source API development ecosystem that streamlines testing and development with features like real-time requests, multiple protocols support, and advanced testing capabilities. The lightweight platform helps developers create requests faster.

    66k•4k•TypeScript•MIT
    Screenshot of hoppscotch website
  4. insomnia icon

    #4insomnia

    A powerful cross-platform API client that supports multiple protocols including GraphQL, REST, and WebSockets. This versatile tool enables debugging, designing, testing, and mocking APIs with advanced storage options and collaboration features.

    35k•1k•JavaScript•Apache-2.0
    Screenshot of insomnia website
  5. firecamp icon

    #5firecamp

    A powerful open-source API development platform offering multi-protocol testing capabilities for Rest, GraphQL, WebSocket, and SocketIO APIs. Streamline your workflow with best-in-class developer experience inspired by VS Code.

    2k•141•TypeScript•AGPL-3.0
    Screenshot of firecamp website
  6. mockoon icon

    #6mockoon

    A powerful desktop application and CLI tool that enables developers to quickly create and run mock APIs locally. This free solution streamlines API development with features like unlimited servers, OpenAPI compatibility, and JSON templating.

    6k•399•TypeScript
    Screenshot of mockoon website
  7. requestly icon

    #7requestly

    A powerful HTTP traffic interceptor and debugging tool that enables developers to modify requests, create API mocks, and debug web applications directly in browsers. Used by over 200,000 developers, this open-source solution works without VPN configuration.

    2k•217•TypeScript
    Screenshot of requestly website
  8. cli icon

    #8cli

    A powerful command-line HTTP client that simplifies API testing and debugging with intuitive syntax, formatted output, and built-in JSON support. Making web service interactions effortless through human-friendly interface.

    34k•3k•Python•BSD-3-Clause
    Screenshot of cli website