The traditional way to test for websockets is this: Although the above example will be technically correct for modern browsers it is important to consider some of the “experimental” implementation of this feature in earlier FireFox (Mozilla) browsers. In FireFox (Mozilla),

Sometimes (when your are developing) you may want to force fetching all content fresh all the time including images, resources such as style sheet etc. To facilitate this you can do the following: Open a new window or tab in Firefox. Type about:config in the address bar. Search for &#