Hurl.it - Hurl makes HTTP requests.
Insomnia REST - The most intuitive cross-platform REST API Client ð´
Postman - The Collaboration Platform for API Development
gURL - gURL is a free, Open Source (GPL) HTTP request generator tool.
Hurl.dev - Hurl is a command line tool that runs HTTP requests defined in a simple plain text format.
RESTClient - RESTClient can be used to test variety of HTTP communications and RESTful webservices.