| c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. |
| SPDX-License-Identifier: curl |
| Long: http3 |
| Tags: Versions |
| Protocols: HTTP |
| Added: 7.66.0 |
| Mutexed: http1.1 http1.0 http2 http2-prior-knowledge http3-only |
| Requires: HTTP/3 |
| Help: Use HTTP v3 |
| See-also: http1.1 http2 |
| Category: http |
| Example: --http3 $URL |
| Multi: mutex |
| Experimental: yes |
| --- |
| Tells curl to try HTTP/3 to the host in the URL, but fallback to earlier |
| HTTP versions if the HTTP/3 connection establishment fails. HTTP/3 is only |
| available for HTTPS and not for HTTP URLs. |
| |
| This option allows a user to avoid using the Alt-Svc method of upgrading to |
| HTTP/3 when you know that the target speaks HTTP/3 on the given host and port. |
| |
| When asked to use HTTP/3, curl will issue a separate attempt to use older HTTP |
| versions with a slight delay, so if the HTTP/3 transfer fails or is very slow, |
| curl will still try to proceed with an older HTTP version. |
| |
| Use --http3-only for similar functionality *without* a fallback. |
