Download > Install > Activate. That's it!

Once activated, the default website field on WordPress post comments will be removed. Discourage backlink spam attempts by not providing the option. Scroll down to this post's comments and you will see the website URL field has been remove.

This code can be pasted into the functions.php file of your child theme or, download and install the plugin for simple code activation.

/*
Plugin Name: Lightweight Plugins - Remove Website URL from Comments
Plugin URI: https://lightweightplugins.com/plugin/remove-website-url-from-comments
Description: Removes website URL field from post comments form and discourage backlink spam.
Version: 1.1
Author: WP Maintenance Experts
Author URI: https://wpmaintenanceexperts.com/
License: GPLv2 or later
*/

function lightweight_plugins_remove_website_url ($fields){
    if(isset($fields['url']))
       unset($fields['url']);
       return $fields;
}
add_filter('comment_form_default_fields', 'lightweight_plugins_remove_website_url');