Glossary · Detection & reputation
Proxy detection
The set of techniques sites use to decide whether a visitor is behind a proxy, ranging from network lookups to behavioural analysis.
Proxy detection is a site asking whether you are who your address claims. The crudest form is a lookup: does this IP belong to a hosting provider, does it appear on a known-proxy list, has it been flagged before. That alone catches most datacenter proxies, because their networks are public knowledge.
Beyond the network, detection turns behavioural. Timing that is too regular, a fingerprint that contradicts the claimed location, DNS or WebRTC that leaks a different origin, dozens of subscribers apparently sharing one address, each is a tell, and detection systems weigh many of them together rather than relying on any single one.
The takeaway is that no proxy is undetectable by its address alone. Staying unflagged is about coherence, an address whose reputation, behaviour and fingerprint all agree, which is why a trusted residential IP used carelessly can still be caught and a modest setup used carefully often is not.
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