---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_PROXY
Section: 3
Source: libcurl
See-also:
  - CURLOPT_HTTPPROXYTUNNEL (3)
  - CURLOPT_PRE_PROXY (3)
  - CURLOPT_PROXYPORT (3)
  - CURLOPT_PROXYTYPE (3)
Protocol:
  - All
Added-in: 7.1
---

# NAME

CURLOPT_PROXY - proxy to use

# SYNOPSIS

~~~c
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY, char *proxy);
~~~

# DESCRIPTION

Set the *proxy* to use for transfers with this easy handle. The parameter
should be a char * to a null-terminated string holding the hostname or dotted
numerical IP address. A numerical IPv6 address must be written within
[brackets].

To specify port number in this string, append `:[port]` to the end of the host
name. The proxy's port number may optionally (but discouraged) be specified
with the separate option CURLOPT_PROXYPORT(3). If not specified, libcurl
defaults to using port 1080 for proxies.

The proxy string may be prefixed with `[scheme]://` to specify which kind of
proxy is used.

Using this option multiple times makes the last set string override the
previous ones. Set it to NULL to disable its use again.

The application does not have to keep the string around after setting this
option.

## `http://`

HTTP Proxy. Default when no scheme or proxy type is specified.

## `https://`

HTTPS Proxy. (with OpenSSL, GnuTLS, mbedTLS, Rustls, Schannel or wolfSSL.)

This uses HTTP/1 by default. Setting CURLOPT_PROXYTYPE(3) to
**CURLPROXY_HTTPS2** allows libcurl to negotiate using HTTP/2 with proxy.

Setting CURLOPT_PROXYTYPE(3) to **CURLPROXY_HTTPS3** allows libcurl to
negotiate using HTTP/3 with proxy. This feature is experimental and requires
a build with HTTP/3 proxy support enabled.

## socks4://

SOCKS4 Proxy.

## `socks4a://`

SOCKS4a Proxy. Proxy resolves URL hostname.

## `socks5://`

SOCKS5 Proxy.

## `socks5h://`

SOCKS5 Proxy. Proxy resolves URL hostname.

##

Without a scheme prefix, CURLOPT_PROXYTYPE(3) can be used to specify which
kind of proxy the string identifies.

When you tell the library to use an HTTP proxy, libcurl transparently converts
operations to HTTP even if you specify an FTP URL etc. This may have an impact
on what other features of the library you can use, such as CURLOPT_QUOTE(3)
and similar FTP specifics that do not work unless you tunnel through the HTTP
proxy. Such tunneling is activated with CURLOPT_HTTPPROXYTUNNEL(3).

Setting the proxy string to "" (an empty string) explicitly disables the use
of a proxy, even if there is an environment variable set for it.

Unix domain sockets are supported for SOCKS proxies. Set `localhost` for the
host part and append the absolute path to the domain socket. For example:
`socks5h://localhost/path/to/socket.sock`

When you set a hostname to use, do not assume that there is any particular
single port number used widely for proxies. Specify it.

When a proxy is used, the active FTP mode as set with *CUROPT_FTPPORT(3)*,
cannot be used.

Doing FTP over an HTTP proxy without CURLOPT_HTTPPROXYTUNNEL(3) set makes
libcurl do HTTP with an FTP URL over the proxy. For such transfers, common FTP
specific options do not work, for example CURLOPT_USE_SSL(3).

# Authentication

The proxy can also be specified with its associated credentials like for
ordinary URLs in the style: `scheme://username:password@hostname`

Alternatively, set them using CURLOPT_PROXYUSERNAME(3) and
CURLOPT_PROXYPASSWORD(3).

# Environment variables

libcurl respects the proxy environment variables named **http_proxy**,
**ftp_proxy**, **sftp_proxy** etc. If set, libcurl uses the specified proxy
for that URL scheme. For an `ftp://` URL, the **ftp_proxy** is
considered. **all_proxy** is used if no protocol specific proxy was set.

If **no_proxy** (or **NO_PROXY**) is set, it is the exact equivalent of
setting the CURLOPT_NOPROXY(3) option.

The CURLOPT_PROXY(3) and CURLOPT_NOPROXY(3) options override environment
variables.

# DEFAULT

NULL

# %PROTOCOLS%

# EXAMPLE

~~~c
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/file.txt");
    curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy.example:80");
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
~~~

# HISTORY

Since 7.14.1 the proxy environment variable names can include the protocol
scheme.

Since 7.21.7 the proxy string supports the socks protocols as "schemes".

Since 7.50.2, unsupported schemes in proxy strings cause libcurl to return
error.

Since 7.52.0, it supports HTTPS proxy for OpenSSL.

Since 7.87.0, it supports HTTPS proxy for GnuTLS, for mbedTLS, Rustls,
Schannel and wolfSSL.

# %AVAILABILITY%

# 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).
