Its very simple to delete the Website URL Field from your WordPress Comments Form.
This will help not encourage spammers wanting to submit posts to get a URL backlink on your site. You should also tick the options to hold posts on more than 1 URL link within the post as well.
To remove the Website field do as follows:-
1 - Log into your /wp-admin
2 - Click Appearance
3 - Click Editer
4 - Click the file named - comments.php
5 - Delete the whole line below. (because the website field is not a required field it will not cause any issues to your existing posts (unlike the name and email fields.)
<p><input type="text" name="url" id="url" value="<?php echo esc_attr($comment_author_url); ?>" size="22" tabindex="3" />
<label for="url"><small><?php _e('Website','cover-wp') ?></small></label></p>
Example With URL
Example Without URL
