Server Diagnostics
Open Server Diagnostics in the left sidebar between Plugins and Hash & Checksum. Enter a hostname, IPv4, IPv6 or URL and select Auto / IPv4 / IPv6 / Both. Start an overview or an individual tool; measurements can be stopped.
Tools include ICMP graphs, progressive traceroute, 12 DNS record types, HTTP protocol comparisons and request timings, compression verification, TLS 1.2/1.3, TCP ports, an SSH handshake without authentication and a WebSocket handshake.
HTTP/3 requires local curl with HTTP3/QUIC and an actual HTTP/3 negotiation over UDP/443. Alt-Svc and HTTP/2 fallback are not proof of support. DNSSEC is not validated; ICMP loss does not mean a server is offline.
History stays local. JSON/CSV/TXT exports omit response bodies, cookies, authentication data and URL queries. Saved runs can be imported, reopened and compared.