If you run a WordPress site with themes, reviews, shopping, and all, then you might want to remove Website field from the comment form of your WordPress. A shopping or theme website doesn’t need a website option. It could be used for product reviews or if they created a support tickets theme that does not require a URL field.
It’s also a great way to prevent spam comments from your blog. Just add following snippet to your functions.php file and it’s done:
add_filter('comment_form_default_fields', 'unset_url_field');
function unset_url_field($fields){
if(isset($fields['url']))
unset($fields['url']);
return $fields;
}