---
name: "CURLOPT_REFERER"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_REFERER"
---

# CURLOPT\_REFERER(3)

the HTTP referer header

## NAME

CURLOPT\_REFERER - the HTTP referer header

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_REFERER, char *where);
```

## DESCRIPTION

Pass a pointer to a null-terminated string as parameter. It is used to set the Referer: header field in the HTTP request sent to the remote server. You can set any custom header with *[CURLOPT\_HTTPHEADER(3)](/CURLOPT_HTTPHEADER/3.md)*.

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

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

## DEFAULT

NULL

## PROTOCOLS

This functionality affects http only

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    /* tell it where we found the link to this place */
    curl_easy_setopt(curl, CURLOPT_REFERER, "https://example.org/me.html");
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in curl 7.1

## RETURN VALUE

*[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLINFO\_REDIRECT\_URL**(3)](/CURLINFO_REDIRECT_URL/3.md), [**CURLINFO\_REFERER**(3)](/CURLINFO_REFERER/3.md), [**CURLOPT\_HTTPHEADER**(3)](/CURLOPT_HTTPHEADER/3.md), [**CURLOPT\_USERAGENT**(3)](/CURLOPT_USERAGENT/3.md)