SumTips

Remove Website and Email Fields from WordPress Comment form

Drop this code into your theme’s functions.php file to remove both ‘website’ and ’email’ field from WordPress’ comment form:

function remove_website_email_field($fields)
{
 $fields = array( $fields['author']); //add $fields['email'] for only website field
 return $fields;
}
add_filter( 'comment_form_default_fields', remove_website_email_field );

Removing ’email’ field will only work if you have “Comment author must fill out name and e-mail” option disabled on Discussion Settings page.

Or, you can also create a plugin to do this. Create a new file with .PHP extension in wp-content/plugins/ with this code:

<?php
function remove_website_email_field( $fields ){
  if(isset($fields['url'], $fields['email'])) //remove $fields['email'] for only website field
    unset($fields['url'], $fields['email']); //remove $fields['email'] for only website field
  return $fields;
}

add_filter( 'comment_form_default_fields', 'remove_website_email_field' );
?>

Plugin would be handy if you are using a theme that receives regular updates. This also gives you the option of easily disabling the feature from your dashboard.