curl/docs/DEPRECATE.md

Items to be removed from future curl releases

If any of these deprecated features is a cause for concern for you, please email the curl-library mailing list as soon as possible and explain to us why this is a problem for you and how your use case cannot be satisfied properly using a workaround.

c-ares 1.16.0

In March 2026, we drop support for all c-ares versions before 1.16.0.

RTMP

RTMP in curl is powered by the 3rd party library librtmp.

• RTMP is barely used by curl users (2.2% in the 2025 survey)
• librtmp has no test cases, makes no proper releases and has not had a single commit within the last year
• librtmp parses the URL itself and requires non-compliant URLs for this
• we have no RTMP tests

Support for RTMP in libcurl gets removed in April 2026.

CMake 3.17 and earlier

We remove support for CMake <3.18 in April 2026.

CMake 3.18 was released on 2020-07-15.

TLS SRP Authentication

Transport Layer Security Secure Remote Password is a TLS feature that does not work with TLS 1.3 or QUIC and is virtually unused by curl users and in general.

TLS SRP support gets removed in August 2026.

Past removals

• axTLS (removed in 7.63.0)
• Pipelining (removed in 7.65.0)
• PolarSSL (removed in 7.69.0)
• NPN (removed in 7.86.0)
• Support for systems without 64-bit data types (removed in 8.0.0)
• NSS (removed in 8.3.0)
• gskit (removed in 8.3.0)
• MinGW v1 (removed in 8.4.0)
• NTLM_WB (removed in 8.8.0)
• space-separated NOPROXY patterns (removed in 8.9.0)
• hyper (removed in 8.12.0)
• Support for Visual Studio 2005 and older (removed in 8.13.0)
• Secure Transport (removed in 8.15.0)
• BearSSL (removed in 8.15.0)
• msh3 (removed in 8.16.0)
• winbuild build system (removed in 8.17.0)
• Windows CE (removed in 8.18.0)
• Support for Visual Studio 2008 (removed in 8.18.0)
• OpenSSL 1.1.1 and older (removed in 8.18.0)
• Support for Windows XP (removed in 8.19.0)
• OpenSSL-QUIC (removed in 8.19.0)