Anonymous web browsing

Anonymous web browsing refers to utilization of the World Wide Web that hides a user's personally identifiable information from websites visited. Anonymous web browsing can be achieved via proxy servers, virtual private networks and other anonymity programs such as Tor. These programs work by sending information through a series of routers in order to hide the source and destination of information. However, there is never a guarantee of anonymity with these servers. These programs are still susceptible to traffic analysis. Proxy servers, which have a central point of knowledge, are also susceptible to collection of data by authorities. Moreover, cookies, browser plugins, and other information can be used to uniquely identify a user even if they have hidden their IP address.

When a user opens a web page, his or her IP address and other computer information (e.g. device fingerprint) become visible to the target web page's server. This information can be used to track the user. The user's IP address can be hidden via a proxy server or a VPN server, though this can be circumvented by just using the wrong browser. These types of servers work by sending a request to the target server from itself rather than from the user directly. For example, if a user requests to visit a link on a web page, the request will—instead of being sent directly to the web site server—be sent to the proxy server, which then relays the request to the targeted internet server. This hides the user's IP address from the target server, as only the proxy server's information is visible.

On the other hand, device fingerprints are relatively resistant to anonymization. While some data can be hidden or spoofed, this can actually make a particular user atypical and thereby less anonymous. Services NoScript and Tor, however, appear to be very effective for creating anonymity.

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Wikipedia