One of the reasons you won't see many of these sites is because of a policy of the same origin. This means that you cannot access the RESTful API located at api.google.com from a web application running, say, www.restfiddle.com , without sending all the API traffic through restfiddle.com server. Sites like JSFiddle can exist (and are widely used) because all processing is done on the client side.
Browser plugins, however, are exempt from policies of the same origin. If you use Chrome, try Postman . If your REST client does not need to be a website, check out SoapUI . IntelliJ IDEA has a good REST client.
source share