demo · v143 · network / connectivity

ALPN benchmark

Configure protocol candidate lists for a simulated WebTransport connection, measure how adding candidates affects negotiation latency, visualize the fallback chain with drag-and-drop reordering, and attempt a real connection to an echo endpoint showing the negotiated selectedProtocol.

1 — Configure protocol candidates

Drag to reorder client priority. The first protocol that matches the server preference list wins.

Server preference order

2 — Latency comparison

Simulated round-trip overhead added per candidate count. Additional candidates require the server to scan its list before confirming the chosen protocol.

Base RTT: 120 ms · Per-candidate overhead: ~2 ms (QUIC TLS ClientHello ALPN extension size growth)

120

3 — Real connection test

Attempt a real new WebTransport(url, { protocols: [...] }) call. The echo endpoint below supports wt-echo.

Click above to attempt a live WebTransport connection with the configured protocols.

4 — Protocol fallback chain visualizer

Drag protocol rows in panel 1 to reorder priority, then click Simulate to see how negotiation plays out under different server configurations.

Server configurations

see also