In WordPress, a commenter can leave their name, e-mail, URL, and comment by default.  The URL field isn’t useful, except maybe to spammers.  I looked for a way to get rid of it and found a wonderful post at http://techhacking.com/2011/02/04/wordpress-how-to-remove-the-website-field-from-the-comment-form/ that does the trick – and very painlessly at that.

The preferred method is to create a file called urlfilter.php and place it in the /wp-content/plugins/ folder.  In the file, the following contents should be added:

<?php
/*
Plugin Name: Remove Website Field
Description: Removes the website field from the comments form
*/
add_filter('comment_form_default_fields', 'url_filtered');
function url_filtered($fields)
{
 if(isset($fields['url']))
 unset($fields['url']);
 return $fields;
}
?>

In the Plugins menu in the Dashboard, Remove Website Field will now show up and just needs to be activated.  That’s it!  It doesn’t get a whole lot easier.

There is an alternate method.  It involves editing the /wp-includes/comment-template.php file to comment out (put two slashes at the beginning of the lines) two lines so they look like:

// 'url'    => '<p><label for="url">' . __( 'Website' ) . '</label>' .
// '<input id="url" name="url" type="text" value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" /></p>',