# Don't Send Referrer Information to Other Sites

> Adds rel="noreferrer" to links in your content that point to other websites, so the sites you link to do not learn which page the visitor came from.

- Type: PHP
- Runs: Frontend only
- Category: [Privacy & Cookies](https://wpide.com/library/category/privacy/)
- Tags: links, referrer, content
- Author: WPIDE Team
- Installs: 0
- Updated: 2026-10-28
- Page: https://wpide.com/library/privacy-noreferrer-external-links/

## Code

```php
// Domains that should still receive the referrer.
$wpide_referrer_allowed = array( 'amazon.com' );

add_filter( 'the_content', function ( $content ) use ( $wpide_referrer_allowed ) {
    if ( false === stripos( $content, '<a' ) || ! class_exists( 'WP_HTML_Tag_Processor' ) ) {
        return $content;
    }

    $own  = wp_parse_url( home_url(), PHP_URL_HOST );
    $tags = new WP_HTML_Tag_Processor( $content );

    while ( $tags->next_tag( 'a' ) ) {
        $host = wp_parse_url( (string) $tags->get_attribute( 'href' ), PHP_URL_HOST );

        if ( ! $host || $host === $own ) {
            continue;
        }

        foreach ( $wpide_referrer_allowed as $domain ) {
            if ( $host === $domain || substr( $host, -strlen( '.' . $domain ) ) === '.' . $domain ) {
                continue 2;
            }
        }

        $rel = preg_split( '/\s+/', trim( (string) $tags->get_attribute( 'rel' ) ), -1, PREG_SPLIT_NO_EMPTY );
        $rel = array_unique( array_merge( $rel, array( 'noreferrer', 'noopener' ) ) );
        $tags->set_attribute( 'rel', implode( ' ', $rel ) );
    }

    return $tags->get_updated_html();
}, 20 );
```

## Notes

Affiliate programs that rely on the referrer to credit you may stop working; add their domains to $wpide_referrer_allowed.

## How to use it

Install the free WPIDE plugin (https://wordpress.org/plugins/wpide/), find "Don't Send Referrer Information to Other Sites" in its snippet library and add it in one click; or create a new PHP snippet in WPIDE (or any code snippets plugin) and paste the code above. More snippets: https://wpide.com/library/