CURLOPT_MAXFILESIZE(3) Introduction to Library Functions
CURLOPT_MAXFILESIZE - maximum file size allowed to download
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_MAXFILESIZE, long size);
Pass a long as parameter. This specifies the maximum accepted size
(in bytes) of a file to download. If the file requested is found
larger than this value, the transfer is aborted and
CURLE_FILESIZE_EXCEEDED is returned. Passing a zero size disables
this, and passing a negative size yields a
CURLE_BAD_FUNCTION_ARGUMENT.
If you want a limit above 2GB, use CURLOPT_MAXFILESIZE_LARGE(3).
If the size is known to be too big before the transfer starts,
libcurl aborts before starting the transfer. If it is instead found
to be too big while the transfer is in progress, libcurl aborts the
transfer once the received bytes exceed the limit.
Since 8.20.0, this option also aborts ongoing transfers once the
decompressed bytes exceed this threshold due to automatic
decompression using CURLOPT_ACCEPT_ENCODING(3).
0, meaning disabled.
This functionality affects all supported protocols
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode result;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
/* refuse to download if larger than 1000 bytes */
curl_easy_setopt(curl, CURLOPT_MAXFILESIZE, 1000L);
result = curl_easy_perform(curl);
}
}
Added in curl 7.10.8
Before curl 8.4.0, the limit was not applied to transfers in
progress.
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).
CURLOPT_MAXFILESIZE_LARGE(3), CURLOPT_MAX_RECV_SPEED_LARGE(3)
libcurl 2026-06-25 CURLOPT_MAXFILESIZE(3)
NAME
CURLOPT_MAXFILESIZE - maximum file size allowed to download
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_MAXFILESIZE, long size);
DESCRIPTION
Pass a long as parameter. This specifies the maximum accepted size
(in bytes) of a file to download. If the file requested is found
larger than this value, the transfer is aborted and
CURLE_FILESIZE_EXCEEDED is returned. Passing a zero size disables
this, and passing a negative size yields a
CURLE_BAD_FUNCTION_ARGUMENT.
If you want a limit above 2GB, use CURLOPT_MAXFILESIZE_LARGE(3).
If the size is known to be too big before the transfer starts,
libcurl aborts before starting the transfer. If it is instead found
to be too big while the transfer is in progress, libcurl aborts the
transfer once the received bytes exceed the limit.
Since 8.20.0, this option also aborts ongoing transfers once the
decompressed bytes exceed this threshold due to automatic
decompression using CURLOPT_ACCEPT_ENCODING(3).
DEFAULT
0, meaning 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/");
/* refuse to download if larger than 1000 bytes */
curl_easy_setopt(curl, CURLOPT_MAXFILESIZE, 1000L);
result = curl_easy_perform(curl);
}
}
AVAILABILITY
Added in curl 7.10.8
HISTORY
Before curl 8.4.0, the limit was not applied to transfers in
progress.
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_MAXFILESIZE_LARGE(3), CURLOPT_MAX_RECV_SPEED_LARGE(3)
libcurl 2026-06-25 CURLOPT_MAXFILESIZE(3)