Classical port — 443

Nothing is served here. That is the point.

You reached this hostname over ordinary, quantum-vulnerable TLS. The demonstration on this domain is deliberately not reachable this way.

The content lives on a listener that accepts post-quantum key exchange and refuses everything else. If it were also served here, over classical TLS, the demonstration would prove nothing.

You are on: pqc2.app2u.click:443 — classical (nginx / OpenSSL 3.0)
The demonstration is on: pqc2.app2u.click:9443 — X25519MLKEM768 only

→ Enter over post-quantum

If that link fails with a TLS error, your browser cannot do post-quantum key exchange yet — which is itself a useful result. Chrome 124+, Edge 124+ or Firefox 132+ will get through.