Not every proxy is something you deliberately configure. A transparent proxy intercepts network traffic automatically, without any client-side configuration — and despite the name suggesting invisibility to the user, it often does the opposite for the destination site: forwarding your real address rather than hiding it.
How transparent proxies work
Rather than you pointing your browser or device at a proxy address, network infrastructure (a corporate network, an ISP, a public Wi-Fi hotspot) automatically routes your traffic through a proxy transparently — you're often unaware it's happening at all. This is commonly used for content filtering, caching, or traffic monitoring at an organizational level, not for user-directed anonymity.
Why "transparent" doesn't mean anonymous
Because transparent proxies are typically deployed for network management rather than user privacy, many forward your original IP address in an X-Forwarded-For header or similar mechanism, so the destination site can still see your real address alongside the proxy's. This is the opposite of what people often assume when they hear "proxy."
How this differs from an anonymity-focused proxy
A proxy explicitly configured for anonymity strips or replaces identifying headers rather than forwarding them — see Anonymous Proxies and the Headers They Leave Behind for how that distinction is tested in practice, since provider labeling alone isn't reliable.
FAQ
How do I know if I'm behind a transparent proxy?
Corporate and school networks often disclose this in their acceptable-use policies; technically, comparing your device's reported address to what an external IP-check tool sees can sometimes reveal interception, though transparent proxies are, by design, meant to be difficult to detect from the client side.