---

c: Copyright (C) Daniel Stenberg, daniel@haxx.se, et al. SPDX-License-Identifier: curl Long: http2-prior-knowledge Tags: Versions Protocols: HTTP Added: 7.49.0 Mutexed: http1.1 http1.0 http2 http3 Requires: HTTP/2 Help: Use HTTP 2 without HTTP/1.1 Upgrade Category: http Multi: boolean See-also:

• http2
• http3 Example:
• --http2-prior-knowledge $URL

---

--http2-prior-knowledge

Tells curl to issue its non-TLS HTTP requests using HTTP/2 without HTTP/1.1 Upgrade. It requires prior knowledge that the server supports HTTP/2 straight away. HTTPS requests still do HTTP/2 the standard way with negotiated protocol version in the TLS handshake.