Checks HTTP, HTTPS, SOCKS4 & SOCKS5 proxies for latency, exit-node geolocation and anonymity level.
Accepted formats: protocol://user:pass@host:port, host:port, host:port:user:pass. Untagged entries default to HTTP unless a protocol is forced above.
For each proxy that's alive, we'll also try reaching the sites checked above. A 2xx/3xx/4xx response means the proxy could reach that site at all — a 403/429 usually means the site is bot-filtering, not that the proxy is broken. A connection failure or timeout means the site is genuinely unreachable through that proxy (often a geo-block or IP ban).