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

Bruno is an open-source IDE for exploring and testing APIs that offers a lightweight alternative to Postman and Insomnia. It stores API collections directly in your filesystem using plain text, enabling seamless collaboration through Git version control while maintaining complete data privacy with offline-only operation.
Bruno is designed for developers, QA engineers, and API teams who value data privacy and want to maintain their API testing workflows in version control. It's ideal for teams seeking a Postman alternative that works offline and integrates seamlessly with Git-based workflows.

Playwright is a framework for Web Testing and Automation. It allows testing Chromium, Firefox and WebKit with a single API.

Open-Source API Development Ecosystem • https://hoppscotch.io • Offline, On-Prem & Cloud • Web, Desktop & CLI • Open-Source Alternative to Postman, Insomnia

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

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

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

Free and open-source API Client & Interceptor.

A list of Free Software network services and web applications which can be hosted on your own servers

Get up and running with Kimi-K2.5, GLM-5, MiniMax, DeepSeek, gpt-oss, Qwen, Gemma and other models.

Production-ready platform for agentic workflow development.

Production-ready platform for agentic workflow development.

User-friendly AI Interface (Supports Ollama, OpenAI API, ...)

Virtual whiteboard for sketching hand-drawn like diagrams

JavaScript API for Chrome and Firefox

JavaScript API for Chrome and Firefox

The world’s fastest framework for building websites.

Playwright is a framework for Web Testing and Automation. It allows testing Chromium, Firefox and WebKit with a single API.