Home page: https://cors-test-srv.appspot.com/
Endpoint: https://cors-test-srv.appspot.com/cors
CORS Proxy is a simple tool that can be use to proxify HTTP GET requests into CORS GET, POST or PUT requests. This tool is not made form prodution, its' goal is to visualise the "preflight" request call made before a CORS request made with PUT.
Since the goal is to see the "preflight" request call made before a CORS, the request must be made from another "Origin" than the server one. I use the web site http://www.test-cors.org. This site is made for this.
Using GET method:
Using POST method:
Using PUT method (now you will seen the preflight OPTIONS request):