fp·check — batch proxy vetting

Paste proxy URLs, one per line (http://user:pass@host:port or socks5://...). Each is routed to the collector; the table shows the proxy's exit device OS (the kernel that terminates TCP at the exit) — the same thing browserleaks reads. Credentials are never shown or stored.

Reading it. The exit TCP-OS is a property of the proxy itself, independent of your client — a mobile proxy running on an Android phone shows Linux/Android; a datacenter Linux VPS also shows Linux/Android (same kernel). To see full cross-layer coherence for a real browser, route that browser through the single-check page. mss<1460 = mobile/tunnel MTU.