Readiness check · Accelerate lane · weight 4

HTTP/3 advertised

The homepage response advertises h3 in its Alt-Svc header.

Why it matters

HTTP/3 runs over QUIC, which copes better with lossy mobile networks and recovers faster when a connection changes.

Turn on HTTP/3 at your CDN. Browsers fall back to HTTP/2 automatically, so the risk is low.

The homepage response advertises h3 in its Alt-Svc header.

Observed: HTTP/3 advertised.

Not observed: HTTP/3 not advertised.

Limit: Read from the homepage response only; other pages or regions may send different headers.

Cloudflare: Enable HTTP/3 (with QUIC) under Speed > Optimization > Protocol Optimization.
Amazon CloudFront: Select HTTP/3 in the distribution's supported HTTP versions.