In simple English
When you build software that talks to other software, you need to send test requests. This tool gives you a clean window to send those requests and read the answers. It supports modern web protocols like REST, GraphQL, and WebSockets. You can save your test collections and share them with teammates. The core application is free to download and use on your computer.
What it is
Insomnia is a cross-platform desktop application built with TypeScript that serves as a feature-rich API client. It helps developers design, debug, test, and mock web APIs using local storage, Git sync, or cloud storage.
What it is good for
Solo builders who need to test backend endpoints, inspect JSON payloads, or design OpenAPI specifications without writing custom scripts.
- Supports REST, GraphQL, gRPC, and WebSockets in one clean interface.
- Offers local-first storage options so your sensitive API keys stay on your machine.
- Includes a command-line tool for running tests in your build pipelines.
- Requires an account for most advanced features and cloud synchronization.
- Some collaboration and security features are locked behind paid subscription tiers.
- Monorepo structure makes building from source heavier than a simple script.
manual curl commands or browser console testing
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git clone https://github.com/Kong/insomnia.git cd insomnia npm install npm run dev