---
name: "CURLOPT_AUTOREFERER"
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_AUTOREFERER"
---

# CURLOPT\_AUTOREFERER(3)

automatically update the referer header

## NAME

CURLOPT\_AUTOREFERER - automatically update the referer header

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_AUTOREFERER, long autorefer);
```

## DESCRIPTION

Pass a long parameter set to 1 to enable this. When enabled, libcurl automatically sets the Referer: header field in HTTP requests to the full URL when it follows a Location: redirect to a new destination.

The automatic referer is set to the full previous URL even when redirects are done cross-origin or following redirects to insecure protocols. This is considered a minor privacy leak by some.

With *[CURLINFO\_REFERER(3)](/CURLINFO_REFERER/3.md)*, applications can extract the actually used referer header after the transfer.

## DEFAULT

0, disabled

## PROTOCOLS

HTTP

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
    /* follow redirects */
    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
    /* set Referer: automatically when following redirects */
    curl_easy_setopt(curl, CURLOPT_AUTOREFERER, 1L);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Along with HTTP

## RETURN VALUE

Returns CURLE\_OK if HTTP is supported, and CURLE\_UNKNOWN\_OPTION if not.

## SEE ALSO

[**CURLINFO\_EFFECTIVE\_URL**(3)](/CURLINFO_EFFECTIVE_URL/3.md), [**CURLINFO\_REDIRECT\_URL**(3)](/CURLINFO_REDIRECT_URL/3.md), [**CURLINFO\_REFERER**(3)](/CURLINFO_REFERER/3.md), [**CURLOPT\_FOLLOWLOCATION**(3)](/CURLOPT_FOLLOWLOCATION/3.md), [**CURLOPT\_REFERER**(3)](/CURLOPT_REFERER/3.md)