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 Flathub apps. The best Insomnia REST Client alternative is Postman, which is free. Other great apps like Insomnia REST Client are Bruno, NativeRest, Yaak and HTTP Toolkit.