A computer-implemented method and system for processing transactions between a client device and a web page. The system includes an adapter for receiving and interpreting a request from the client device, wherein the adapter is configured to interface with the client device. A generator retrieves a web page specified by the request. A transcoder receives the retrieved web page and applies a transcoding rule to extract data from the web page. The transcoding rule used is one of a set of predefined rules relating to the web page. The transcoder also transforms the data into a standardized form so that the adapter can then modifying the standardized data into a compatible form for display by the client device. Therefore, web based transactions can be performed by a variety of client devices, including portable, wireless and voice-based devices.