How to add custom content to the WordPress comments form

To customize the built-in WordPress comments form you could use plugins, but those often slow down your site. A better approach to add custom content to the comments form is by using the WordPress comments form hooks.

List of WordPress Comments Form Hooks

There are seven WordPress comments hooks. Some of them are not available depending the discussion settings (learn more).

1. comment_form_before
2. comment_form_top
3. comment_form_before_fields
4. comment_form_after_fields
5. comment_form
6. comment_form_must_log_in_after
7. comment_form_after

The hooks speak for themselves, but for more comprehensive look see the WordPress Comments Form – Visual Hook Guide.

PHP Snippet: Add custom content above the WordPress comments fields

Lets see how to add our custom content ‘comment policy text’ above the comment fields. To place the content there we’ll use comment_form_top hook.

add_action('comment_form_top', 'webroom_add_comment_notice');
function webroom_add_comment_notice() {
    echo '<p>Comment policy: All comments are manually moderated and those deemed to be spam or promotional will be deleted.</p>';
}

PHP Snippet: Add custom content below the WordPress comments fields

Lets see how to add our custom content ‘comment policy text’ below the comment fields and above the Post comment button. To place the content there we’ll use comment_form_after_fields hook.

add_action('comment_form_after_fields', 'webroom_add_comment_notice');
function webroom_add_comment_notice() {
    echo '<p>Comment policy: All comments are manually moderated and those deemed to be spam or promotional will be deleted.</p>';
}

PHP Snippet: Add custom content below the Post comment button in WordPress comments

Lets see how to add our custom content ‘comment policy text’ below the comment fields and above the Post comment button. To place the content there we’ll use comment_form_after hook.

add_action('comment_form_after', 'webroom_add_comment_notice');
function webroom_add_comment_notice() {
    echo '<p>Comment policy: All comments are manually moderated and those deemed to be spam or promotional will be deleted.</p>';
}

Note that depending the WordPress discussion settings you have some hooks are not available. For example if only logged in users can comment or the comments are disabled for particular post. Learn which WordPress comments form hooks are active depending the settings you have in the WordPress Comments Visual Hooks Guide.

Learn more about Comments in WordPress in the official documentation.

Related reading
How to add custom CSS or JS code to WordPress admin panel
WordPress: send an email on new comments
WooCommerce admin: custom order meta column