What is a JVS file? A JVS file is a JavaScript-based configuration file used by web browsers to automatically determine whether to use a proxy server when connecting to specific websites. It contains a function called FindProxyForURL() , which evaluates the requested URL and decides whether the browser should route the request through a proxy server or connect directly. JVS files help organizations manage and control Internet access without requiring users to configure proxy settings manually.

More Information Network administrators often distribute JVS files, which browser or system network settings then reference. JVS files serve the same purpose as .PAC (Proxy Auto-Config) files, though they are less commonly used. Whether a file is saved as JVS or PAC depends on the system or software generating it. JVS and PAC files have the same structure and function despite the different extensions, relying on JavaScript logic to guide how browsers handle network requests. NOTE: Netscape Communications introduced the JavaScript Proxy Auto-Config format in the mid-1990s. Then, other vendors, such as Microsoft and Apple, adopted and extended it as proxy management became an essential part of enterprise network configuration.