Top 5 Open Source Alternatives to Postman in 2024

Discover the Best Free and Open-Source API Testing Tools to Boost Your Development Workflow

If you're looking for open-source alternatives to Postman in 2024, here are five of the best options, each offering unique features for API development, testing, and collaboration:

1. Insomnia

Insomnia is a popular open-source API client known for its intuitive interface and support for REST and GraphQL requests. It's great for testing, debugging, and managing APIs with ease.

• Key Features:

  • Supports REST, GraphQL, and WebSocket requests

  • Plugin support to extend functionality

  • Easy environment and cookie management

  • Data export/import via JSON and other formats

2. Hoppscotch

Formerly known as Postwoman, Hoppscotch is an open-source API testing tool that's lightweight and fast. It offers a clean UI, supports real-time testing, and has a wide array of features for HTTP requests and WebSocket connections.

• Key Features:

  • Real-time WebSocket and SSE connections

  • Supports multiple request types: REST, GraphQL, and more

  • Sync data with your GitHub or Google accounts

  • Lightweight and highly responsive

3. Kong API Gateway

Kong is an open-source API gateway built on NGINX. While it's more focused on API management than direct testing, it provides great tools for proxying, authentication, traffic control, and more. It's ideal for enterprises looking to control and optimize API traffic.

• Key Features:

  • API gateway and API management

  • Built-in rate-limiting, logging, and authentication

  • Scalable, lightweight, and cloud-native

  • Plugin ecosystem for customization

4. Thunder Client (VSCode Extension)

Thunder Client is a lightweight, open-source HTTP client built into VSCode for developers who prefer to stay within their code editor. It's perfect for those who need a basic yet functional API testing tool without leaving the IDE.

• Key Features:

  • Simple and easy-to-use UI within VSCode

  • Supports REST APIs and GraphQL

  • Request history and environment variables support

  • Lightweight, fast, and easy to install

5. SoapUI

SoapUI is a popular open-source tool for testing APIs, especially SOAP-based web services. It supports functional and performance testing, making it suitable for developers and testers. SoapUI provides powerful features such as automated testing, support for multiple protocols (SOAP, REST, JMS, JDBC), and the ability to create complex test scenarios with minimal effort. It also offers a user-friendly interface for designing and executing tests, along with robust reporting capabilities. SoapUI is ideal for teams working on enterprise-level projects requiring extensive API testing.

• Key Features:

  • Supports both REST and SOAP protocols

  • Data-driven testing

  • Load and performance testing

  • Customizable with Groovy scripting

  • Extensive support for security testing

• Best For: Enterprises or developers focusing on both SOAP and REST API testing with advanced testing needs.

Conclusion

Whether you need a comprehensive testing suite like SoapUI, or a lightweight tool like Hoppscotch, these alternatives provide powerful open-source solutions for API testing in 2024. Each tool has its strengths, making it easier for teams to choose the one that best fits their workflow and project requirements.