You can use A4Proxy with another local proxy program, like Webwasher or Proxomitron. The idea is to form a “chain”, where your browser first connects to that other local proxy server, and then that program connects to A4Proxy. From the point of view of A4Proxy, there will be no difference, it won’t even “know” that there is another program between it and the web browser.
Below is an example for Webwasher. Set up your browser to use WebWasher (127.0.0.1 port 8080), and then to set up WebWasher to use A4Proxy (127.0.0.1 port 80).
Configuration of the browser. A4Proxy supports three web communication protocols (HTTP, Secure HTTP and FTP), while WebWasher supports only one (HTTP). This requires that you configure the browser in the following way: For HTTP protocol, enter 127.0.0.1 port 8080 (this will direct all HTTP requests to the WebWasher program); For Secure HTTP and FTP, enter 127.0.0.1 port 80 (this will direct requests made with these protocols to A4Proxy)
Configuration of WebWasher (v.2.1.1). Right-click its tray icon and choose Preferences in the menu On the left of the configuration panel that will appear, you will see a tree of available options. Open the top sub-tree called “Proxy Engine”, there are two options in that subtree: Client and Server. You should enable the “Client” option; when you select it, on the right part of the window some options will become available. You will need the top text box “HTTP 1”, titled “Address of proxy server to use”. Enter 127.0.0.1 there, and enter 80 in the Port text box on the right (this will make WebWasher to redirect all requests to A4Proxy program). Make sure that in the Proxy Type drop-down list below the setting of “CERN compatible (default)” is selected. Click OK. Right-click WebWasher icon again. In the menu, mark the “Use a proxy server” option. When this option is selected, WebWasher sends requests to A4Proxy; when it is not selected, A4Proxy is not used and you are not anonymous.
That’s all. After you set it up, look at A4Proxy icon to see if it is really used: the icon must be flashing when you are surfing. Please let me know if you have any difficulty. Please notice, that with this configuration you will be able to “switch off” A4Proxy program (that is, “switch off” the anonymity feature) in two different places: in WebWasher (the “Use a proxy server” option, when selected – you are anonymous) and in A4Proxy itself (“Direct Connection” option, when selected – you are NOT anonymous). Please don’t mix them up. The best way is to never use the option in WebWasher (always keep it selected) and use A4Proxy’s own settings to switch it on and off – the A4Proxy icon will change to indicate its current status.