---
name: "CURLOPT_REFERER"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
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.

## DEFAULT

NULL

## PROTOCOLS

HTTP

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    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");
    curl_easy_perform(curl);
  }
}
```

## AVAILABILITY

If built with HTTP support

## RETURN VALUE

Returns CURLE\_OK if HTTP support is enabled, CURLE\_UNKNOWN\_OPTION if not, or CURLE\_OUT\_OF\_MEMORY if there was insufficient heap space.

## 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)