curl/docs/libcurl/opts/CURLOPT_MAXFILESIZE.md
Daniel Stenberg 89f38c168c
CURLOPT_MAXFILESIZE: clarify this also works for on-going transfers
It was not really clear, but it has worked like this since 8.4.0 which
now is a while.

Closes #21582
2026-05-13 09:45:33 +02:00

1.9 KiB

c SPDX-License-Identifier Title Section Source See-also Protocol Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLOPT_MAXFILESIZE 3 libcurl
CURLOPT_MAXFILESIZE_LARGE (3)
CURLOPT_MAX_RECV_SPEED_LARGE (3)
All
7.10.8

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%

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%

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).