Voiden.md is an offline-first, Git-native API workspace that unifies specs, docs, tests, and mocks using programmable Markdown blocks. Build APIs the way you actually work.



Insomnia REST Client is described as 'A powerful REST API Client with cookie management, environment variables, code generation, and authentication for Mac, Window, and Linux' and is a very popular API Client in the development category. There are more than 50 alternatives to Insomnia REST Client for a variety of platforms, including Mac, Windows, Linux, Web-based and Google Chrome apps. The best Insomnia REST Client alternative is Bruno, which is both free and Open Source. Other great apps like Insomnia REST Client are Postman, NativeRest, Yaak and Hoppscotch.
Voiden.md is an offline-first, Git-native API workspace that unifies specs, docs, tests, and mocks using programmable Markdown blocks. Build APIs the way you actually work.



Treblle is a federated API Intelligence platform delivering full API visibility, security, and control from one integration point.



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



gRPC is a modern open source high performance Remote Procedure Call (RPC) framework that can run in any environment. It can efficiently connect services in and across data centers with pluggable support for load balancing, tracing, health checking and authentication.

Kreya is a GUI client for gRPC, REST and WebSocket APIs with innovative features for environments, authorizations and more.








Thunder Client is a hand-crafted lightweight Http Client extension for Visual Studio Code. No separate download needed, Just install the extension from VS Code marketplace.


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.








RecipeUI is rethinking how we use API tools like Postman or Insomnia. We're starting off with TypeScript powered API requests and API collections you can run in seconds!

EchoAPI is an all-in-one API development collaboration platform that offers essential features like API debugging, design, automated testing, stress testing, and documentation generation.
Used httpyac CLI tool underneath, which helps you execute _.http and _.rest files. This can be used to quickly execute a single *.http file, but also to execute all files in a folder. httpyac supports HTTP, Rest, GraphQL, WebSocket und gRPC...

Requires an account before you're able to use it. If you're moving from Insomnia because they required accounts, this application may not be the one you're looking for.