CURLINFO_CONTENT_LENGTH_DOWNLOAD - get content-length of download

Added in curl 7.6.1

Deprecated since 7.55.0.

Pass a pointer to a double to receive the content-length of the download. This is the value read from the Content-Length: field. Since 7.19.4, this returns -1 if the size is not known. CURLINFO_CONTENT_LENGTH_DOWNLOAD_T(3) is a newer replacement that returns a more sensible variable type.

int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode res; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); /* Perform the request */ res = curl_easy_perform(curl); if(!res) { /* check the size */ double cl; res = curl_easy_getinfo(curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl); if(!res) { printf("Size: %.0f\n", cl); } } } }

CURLINFO_CONTENT_LENGTH_DOWNLOAD - get content-length of download

This functionality affects all supported protocols

curl_easy_getinfo(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).

CURLINFO_CONTENT_LENGTH_UPLOAD(3), curl_easy_getinfo(3), curl_easy_setopt(3) libcurl 2025-06-16 CURLINFO_CONTENT_LENGTH_DOWNLOAD(3)

#include <curl/curl.h> CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD, double *content_length);