X-Forwarded-For

X-Forwarded-For (XFF) can carry client IP addresses through a proxy chain. An address is not proof of a person's identity, and client-supplied entries can be forged. Only entries added through a configured, trusted chain should inform security decisions. See MDN's XFF reference.

Labels such as transparent, anonymous and elite describe test observations, not anonymity guarantees. A Via header can indicate an intermediary; its absence proves little. Treat labels in the free proxy list as filters. An IP tool checks the reported exit address, not every header received by a destination.

Use the tools to inspect your reported exit IP. To check XFF, send a request through the same client and protocol to a service that returns received headers. Neither the free list nor an authenticated proxy or VPN label proves that every request hides all identifying information.