CURLOPT_MAX_RECV_SPEED_LARGE - Man Page

#include <curl/curl.h>

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

Pass a curl_off_t as parameter. If a download exceeds this maxspeed (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_BUFFERSIZE(3), libcurl might download faster than the set limit initially.

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

0, disabled

This functionality affects all supported protocols

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode ret;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    /* cap the download speed to 31415 bytes/sec */
    curl_easy_setopt(curl, CURLOPT_MAX_RECV_SPEED_LARGE, (curl_off_t)31415);
    ret = curl_easy_perform(curl);
  }
}

Added in curl 7.15.5

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

CURLOPT_LOW_SPEED_LIMIT(3), CURLOPT_MAX_SEND_SPEED_LARGE(3), CURLOPT_TIMEOUT(3)

curl_easy_pause(3), curl_easy_setopt(3), CURLOPT_BUFFERSIZE(3), CURLOPT_CONNECTTIMEOUT(3), CURLOPT_CONNECTTIMEOUT_MS(3), CURLOPT_LOW_SPEED_LIMIT(3), CURLOPT_MAXFILESIZE(3), CURLOPT_MAXFILESIZE_LARGE(3), CURLOPT_MAX_SEND_SPEED_LARGE(3), CURLOPT_RANGE(3), CURLOPT_TCP_KEEPALIVE(3), libcurl-symbols(3).