1 Long: http2-prior-knowledge 2 Tags: Versions 3 Protocols: HTTP 4 Added: 7.49.0 5 Mutexed: http1.1 http1.0 http2 6 Requires: HTTP/2 7 Help: Use HTTP 2 without HTTP/1.1 Upgrade 8 Category: http 9 Example: --http2-prior-knowledge $URL 10 --- 11 Tells curl to issue its non-TLS HTTP requests using HTTP/2 without HTTP/1.1 12 Upgrade. It requires prior knowledge that the server supports HTTP/2 straight 13 away. HTTPS requests will still do HTTP/2 the standard way with negotiated 14 protocol version in the TLS handshake. 15