Performance Check n°92 / 120

HTTP/3 (QUIC)

HTTP/3 is the 3rd version of the HTTP protocol. Unlike HTTP/1.1 and HTTP/2 which use TCP, HTTP/3 uses QUIC (UDP-based). This eliminates TCP'…

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How it works

How TheSiteFuse checks "HTTP/3 (QUIC)"

HTTP/3 is the 3rd version of the HTTP protocol. Unlike HTTP/1.1 and HTTP/2 which use TCP, HTTP/3 uses QUIC (UDP-based). This eliminates TCP's "head-of-line blocking" problem and reduces latency, especially on unstable mobile connections. The server announces support via the "Alt-Svc: h3" header.

Why it matters

Real-world impact of "HTTP/3 (QUIC)"

HTTP/3 improves performance on slow or unstable connections (mobile, weak Wi-Fi), which represent the majority of global web traffic. CDNs like Cloudflare enable it automatically. For dedicated hosting, it's a configuration to request from the host.

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