API testing tool. Which allows web developers to create and test custom HTTP requests.
Platforms
- Mac
- Windows
- Linux
- Chrome OS
- AppImageHub
- Google Chrome
- Chromium
Poland
EU



Insomnium has been discontinued. Similar apps include Bruno, which is open source with a free version. Other options are Postman, Insomnia REST Client, Yaak and Hoppscotch. There's no shortage of API Clients like Insomnium, with more than 25 alternatives for Mac, Linux, Windows, the web and Chrome OS.
API testing tool. Which allows web developers to create and test custom HTTP requests.



HarborClient is a free, open-source desktop API client for macOS, Windows, and Linux. It gives you a familiar Postman-style workspace—collections, environments, request scripts, and a tabbed editor—while keeping your work on your machine or on storage you control.

Cartero is a graphical HTTP client that can be used as a developer tool to test web APIs and perform all kind of HTTP requests to web servers. It is compatible with any REST, SOAP or XML-RPC API and it supports multiple request methods as well as attaching body payloads to...

Upcoming API testing tool in beta, built in GoLang, supporting HTTP/gRPC, workspaces, environments, request management, and various content types. Features include dark mode, local data storage, Postman import, environment variable setting, and request chaining.




Build, test, and debug your APIs with a self-hosted tool that does what you actually need. Scripts, environments, OAuth 2.0, code generation, and an AI wizard that builds collections from your docs — no account required, no limits.




Zaku is a native Rust, local-first, open-source API client engineered for speed and productivity.

All the user-friendliness of our Terminal version, now wrapped up in a sleek graphical interface.



A cross-platform HTTP client desktop application for testing HTTP and REST APIs, WebSocket, GraphQL (including subscriptions) and gRPC endpoints.




Native API client for Windows & Linux — collections, environments, OpenAPI import, Git sync, request chaining, and response testing.




RequesterX is a free desktop HTTP client for API testing and development. Organize requests into nested collections, use environment variables for easy context switching, generate code snippets in 13 languages, and keep everything stored locally — no account required.
