Postman - The Collaboration Platform for API Development
Insomnia REST - The most intuitive cross-platform REST API Client ð´
RESTClient - RESTClient can be used to test variety of HTTP communications and RESTful webservices.
Postwoman - An online, open source API request builder
Hurl.it - Hurl makes HTTP requests.
NativeRest - NativeRest is a native REST API client for Windows. NativeRest desktop application is not using Electron, runs fast, uses less memory and CPU.