Suzanne

For Genesis child themes that output HTML5 only.
This plugin adds an entry field just below the title field on all post, 
page and custom post type edit screens. It allows you to specify a 
subtitle for the content and then outputs the result in an H2 tag just 
under the entry-title where you’d expect to find it.
This plugin is for use with Genesis HTML5 child themes only because it 
uses the hook, genesis_entry_header to position the output after the 
title but before the post-info.

Genesis Subtitles

For Genesis child themes that output HTML5 only.

Dropndot Solutions

Dropndot Post Subtitle allows you to easily add subtitles (subheadings) to your WordPress posts, pages, and custom post types. The plugin integrates seamlessly with both Gutenberg and Classic Editor, and provides full support for modern WordPress development with WPGraphQL and REST API integration.
<h4>Features</h4>
<ul>
<li>Gutenberg Sidebar Panel – Easy-to-use subtitle field in the document sidebar</li>
<li>Classic Editor Support – Subtitle field appears right after the title</li>
<li>Custom Post Types – Enable subtitles for any post type</li>
<li>WPGraphQL Integration – Query subtitles in your GraphQL queries</li>
<li>REST API Support – Access subtitles via WordPress REST API</li>
<li>Quick Edit – Edit subtitles directly from the posts list</li>
<li>Admin Columns – See subtitles at a glance in the admin</li>
<li>Shortcodes – Display subtitles anywhere with <code>[dropposu_subtitle]</code></li>
<li>Developer Friendly – Simple PHP functions for theme integration</li>
</ul>
<h4>Usage</h4>
Shortcode:
<pre><code>[dropposu_subtitle]
</code></pre>
In Theme Templates:
<pre><code><?php dropposu_subtitle(); ?>
</code></pre>
With HTML Wrapper:
<pre><code><?php dropposu_subtitle(0, '<h2 class="subtitle">', '</h2>'); ?>
</code></pre>
WPGraphQL:
<pre><code>query {
 post(id: "/my-post/", idType: SLUG) {
 title
 subtitle
 }
}
</code></pre>
REST API:
Access via <code>/wp-json/wp/v2/posts/123</code> – response includes <code>dropposu_subtitle</code> field.
<h3>Developer Documentation</h3>
<h4>Functions</h4>
dropposu_subtitle( $post_id, $before, $after )
Display the subtitle.
Parameters: 
* <code>$post_id</code> (int) – Post ID. Default: current post 
* <code>$before</code> (string) – HTML before subtitle 
* <code>$after</code> (string) – HTML after subtitle
get_dropposu_subtitle( $post_id, $before, $after )
Get the subtitle (returns string, does not echo).
Parameters: 
* <code>$post_id</code> (int) – Post ID. Default: current post 
* <code>$before</code> (string) – HTML before subtitle 
* <code>$after</code> (string) – HTML after subtitle
<h3>Support</h3>
For support, please visit the plugin settings page or contact the developer at https://dropndot.com

Dropndot Post Subtitle

Add subtitles to posts, pages, and custom post types. Supports Gutenberg, Classic Editor, WPGraphQL, REST API, and shortcodes.

Genesis Subtitles vs Dropndot Post Subtitle