1--- 2c: Copyright (C) Daniel Stenberg, <[email protected]>, et al. 3SPDX-License-Identifier: curl 4Long: no-npn 5Tags: Versions HTTP/2 6Protocols: HTTPS 7Added: 7.36.0 8Mutexed: 9Requires: TLS 10Help: Disable the NPN TLS extension 11Category: deprecated 12Multi: boolean 13See-also: 14 - no-alpn 15 - http2 16Example: 17 - --no-npn $URL 18--- 19 20# `--no-npn` 21 22curl never uses NPN, this option has no effect (added in 7.86.0). 23 24Disable the NPN TLS extension. NPN is enabled by default if libcurl was built 25with an SSL library that supports NPN. NPN is used by a libcurl that supports 26HTTP/2 to negotiate HTTP/2 support with the server during https sessions. 27