1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Long: http3-only 5Tags: Versions 6Protocols: HTTP 7Added: 7.88.0 8Mutexed: http1.1 http1.0 http2 http2-prior-knowledge http3 9Requires: HTTP/3 10Help: Use HTTP v3 only 11Category: http 12Multi: mutex 13See-also: 14 - http1.1 15 - http2 16 - http3 17Example: 18 - --http3-only $URL 19--- 20 21# `--http3-only` 22 23Instructs curl to use HTTP/3 to the host in the URL, with no fallback to 24earlier HTTP versions. HTTP/3 can only be used for HTTPS and not for HTTP 25URLs. For HTTP, this option triggers an error. 26 27This option allows a user to avoid using the Alt-Svc method of upgrading to 28HTTP/3 when you know that the target speaks HTTP/3 on the given host and port. 29 30This option makes curl fail if a QUIC connection cannot be established, it 31does not attempt any other HTTP versions on its own. Use --http3 for similar 32functionality *with* a fallback. 33