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.

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)