How to add nofollow to specific or all links in the_content in WordPress

To add the nofollow attribute to specific or all links in the the_content function in WordPress, you can use the wp_rel_nofollow function in your theme’s functions.php file.

Here’s an example of how you can use this function to add the nofollow attribute to all links in the the_content function:

// Add nofollow to specific or all links in the_content
// More snippets at wpunplugged.com 

add_filter( 'the_content', 'my_nofollow_content_filter' );
function my_nofollow_content_filter( $content ) {
  return wp_rel_nofollow( $content );
}

This will add the nofollow attribute to all links in the the_content function.

If you only want to add the nofollow attribute to specific links in the the_content function, you can use a regular expression to match the specific links you want to target and add the nofollow attribute to them. Here’s an example of how you can do this:

// Add nofollow to specific or all links in the_content
// More snippets at wpunplugged.com 

add_filter( 'the_content', 'my_nofollow_specific_links_filter' );
function my_nofollow_specific_links_filter( $content ) {
  $pattern = '/<a(.*?)href=[\'"](http:\/\/example\.com)[\'"](.*?)>/i';
  $replacement = '<a$1href="$2" rel="nofollow"$3>';
  $content = preg_replace( $pattern, $replacement, $content );
  return $content;
}

This will add the nofollow attribute to all links that point to the http://example.com domain. You can modify the regular expression to match the specific links you want to target.