CURLMOPT_PIPELINING(3) Library Functions Manual CURLMOPT_PIPELINING(3)
NAME
CURLMOPT_PIPELINING - enable HTTP multiplexing
SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING, long bitmask);
DESCRIPTION
Pass in the correct value in the bitmask parameter to instruct libcurl
to enable multiplexing for this multi handle.
With multiplexing enabled, libcurl attempts to do multiple transfers
over the same connection when doing parallel transfers to the same
hosts.
CURLPIPE_NOTHING (0)
Make no attempts at multiplexing.
CURLPIPE_HTTP1 (1)
This bit is deprecated and has no effect since version 7.62.0.
CURLPIPE_MULTIPLEX (2)
If this bit is set, libcurl tries to multiplex the new transfer
over an existing connection if possible. This requires HTTP/2 or
HTTP/3.
DEFAULT
CURLPIPE_MULTIPLEX
PROTOCOLS
This functionality affects http only
EXAMPLE
int main(void)
{
CURLM *m = curl_multi_init();
/* try HTTP/2 multiplexing */
curl_multi_setopt(m, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
}
HISTORY
The multiplex support bit was added in 7.43.0. HTTP/1 Pipelining support
was disabled in 7.62.0.
Since 7.62.0, CURLPIPE_MULTIPLEX is enabled by default.
Before that, default was CURLPIPE_NOTHING.
AVAILABILITY
Added in curl 7.16.0
RETURN VALUE
curl_multi_setopt(3) returns a CURLMcode indicating success or error.
CURLM_OK (0) means everything was OK, non-zero means an error occurred,
see libcurl-errors(3).
SEE ALSO
CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3), CURLMOPT_CON-
TENT_LENGTH_PENALTY_SIZE(3), CURLMOPT_MAXCONNECTS(3), CURL-
MOPT_MAX_HOST_CONNECTIONS(3), CURLMOPT_MAX_PIPELINE_LENGTH(3), CURL-
MOPT_PIPELINING_SITE_BL(3)
libcurl 2026-07-12 CURLMOPT_PIPELINING(3)
Generated by dwww version 1.16 on Sat Oct 3 05:57:11 CEST 2026.