CURLOPT_MAX_SEND_SPEED_LARGE(3) Introduction to Library Functions

NAME

CURLOPT_MAX_SEND_SPEED_LARGE - rate limit data upload speed

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_MAX_SEND_SPEED_LARGE,
curl_off_t maxspeed);

DESCRIPTION

Pass a curl_off_t as parameter with the maxspeed. If an upload
exceeds this speed (counted in bytes per second) the transfer pauses
to keep the average speed less than or equal to the parameter value.
Defaults to unlimited speed.

This is not an exact science. libcurl attempts to keep the average
speed below the given threshold over a period time.

If you set maxspeed to a value lower than
CURLOPT_UPLOAD_BUFFERSIZE(3), libcurl might "shoot over" the limit on
its first send and still send off a full buffer.

This option does not affect transfer speeds done with FILE:// URLs.

DEFAULT

0, disabled

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode result;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
/* cap the upload speed to 1000 bytes/sec */
curl_easy_setopt(curl, CURLOPT_MAX_SEND_SPEED_LARGE, (curl_off_t)1000);
/* (set some upload options as well) */
result = curl_easy_perform(curl);
}
}

AVAILABILITY

Added in curl 7.15.5

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).

SEE ALSO

CURLOPT_LOW_SPEED_LIMIT(3), CURLOPT_MAX_RECV_SPEED_LARGE(3)

libcurl 2026-01-08 CURLOPT_MAX_SEND_SPEED_LARGE(3)