The essential points from this guide -- each one is explained in detail below.
Elite proxies strip all identifying headers -- the target sees only the proxy IP.
Anonymous proxies reveal a proxy is being used but hide your real IP.
Transparent proxies pass your real IP in X-Forwarded-For headers.
Test for WebRTC and DNS leaks, which can reveal your real IP even through an elite proxy.
Proxies are classified into three anonymity levels. Transparent proxies forward your real IP in the X-Forwarded-For header -- the target knows both the proxy IP and your real IP. Anonymous proxies reveal that a proxy is being used (via the Via header) but do not expose your real IP. Elite (high-anonymity) proxies strip all proxy-related headers -- the target sees only the proxy's IP address with no indication a proxy is involved.
Send a request through your proxy to httpbin.org/headers and examine the response:
curl -x http://USER:PASS@proxy:port https://httpbin.org/headersCheck for: X-Forwarded-For (should be absent or show only the proxy IP), Via (should be absent for elite proxies), X-Real-IP (should be absent). If your real IP appears in any header, the proxy is not providing elite anonymity.
Even elite proxies can be circumvented by browser-level leaks. WebRTC can reveal your real IP through STUN requests that bypass the proxy. DNS leaks occur when DNS queries go directly to your ISP instead of through the proxy. Test for both using dedicated leak testing tools. In Firefox, disable WebRTC via about:config (media.peerconnection.enabled = false). In Chrome, use extensions like WebRTC Leak Prevent.
Ready to put this into practice? Test your proxy anonymity level
KnoxProxy Research Team · Technical Content
Network engineers and proxy infrastructure specialists with 10+ years in anti-bot systems, web scraping, and IP routing.
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