Open Source API Development & Testing Tools Projects

Tools for designing, testing, documenting, and managing APIs used by developers and engineering teams.

Bruno

Opensource IDE For Exploring and Testing API's (lightweight alternative to Postman/Insomnia)

Alternative to:

Postman

HTTPie

Open-source command-line and desktop HTTP client with intuitive syntax, JSON support, and built-in auth — a developer-friendly Postman alternative.

Alternative to:

Postman

Hoppscotch

Open source API development ecosystem - https://hoppscotch.io (open-source alternative to Postman, Insomnia)

Alternative to:

Postman

Hurl

Run and test HTTP requests with plain text — a simple yet powerful command-line tool for API testing.

Alternative to:

Postman

Insomnia

The open-source, cross-platform API client for GraphQL, REST, WebSockets, SSE and gRPC. With Cloud, Local and Git storage.

Alternative to:

Postman

Maxun

Open-source no-code platform for web scraping, crawling, search and AI data extraction.

Alternative to:

Firecrawl

Scalar

Scalar is an open-source API platform:　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　🌐 Modern Rest API Client　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　📖 Beautiful API References　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　✨ 1st-Class OpenAPI/Swagger Support

Alternative to:

Postman

Voiden

Design, test and document APIs in plain Markdown with a git-native, offline-first approach.

Alternative to:

Postman

Yaak

The most intuitive desktop API client. Organize and execute REST, GraphQL, WebSockets, Server Sent Events, and gRPC 🦬

Alternative to:

Postman