One Crayon

<p>Markup to Featured Image will automatically generate a featured image when you publish a post, with the intent of allowing you to publish posts with featured images from third-party clients like MarsEdit.</p>
<p>To add a featured image to your post, include one of the following markup variants in your post’s content:</p>
<pre><code><img src="/path/to/image.jpg" data-featured-image="keep" />
<img src="/path/to/image.jpg" data-featured-image="strip" />

</code></pre>
<p>If you use an <code><img></code> element, the values of the <code>data-featured-image</code> attribute specify whether the image should be displayed when the post is shown on your site (<code>keep</code>) or ignored when the post is displayed (<code>strip</code>). The order of attributes in your <code><img></code> tag (and whether you include other attributes, like width/height, title, alt, etc.) doesn’t matter. You can make it as complicated or simple as you like.</p>
<p>If the post already has a featured image, the plugin will do nothing (version 1.0 does <em>not</em> allow updating the thumbnail by updating the markup).</p>

Markup to Featured Image

Automatically set the featured image (formerly the post thumbnail) for a post based on custom markup in the body text.

cyrillbolliger

<p>Easily control the visibility of the featured image on singular posts and pages–while keeping it visible in archive pages, query loops, and other list views. This plugin provides a simple checkbox option within the post editor, allowing you to enable or disable the display of the featured image on individual posts and pages.</p>
<h4>Key Features</h4>
<ul>
<li>Show or hide the featured image on singular pages and posts.</li>
<li>Seamlessly integrates with the WordPress post editor.</li>
<li>Simple checkbox toggle—no technical knowledge needed.</li>
<li>Compatible with most themes.</li>
<li>Supports WooCommerce product pages.</li>
<li>Lightweight and optimized for performance.</li>
<li>100% free—no ads, no upsells, no premium versions!</li>
</ul>
<p>Perfect for bloggers, content creators, and developers who want precise control over the visibility of featured images on a per-post basis.</p>
<h4>Important Notice</h4>
<p>If your theme uses a custom method to load the featured image (such as the Twenty Seventeen theme), this plugin may not work. To ensure compatibility, use standard WordPress functions like <code>get_the_post_thumbnail()</code>, <code>wp_get_attachment_image()</code>, or the <a href="https://wordpress.org/support/article/post-featured-image-block/" rel="ugc">Post Featured Image</a> block.</p>
<p>Additionally, by default, this plugin only hides the featured image when it is loaded inside the loop. If your theme loads it outside the loop check out the first FAQ entry for a solution.</p>


Conditionally display featured image on singular posts and pages

It works!

I was able to get this working on Genesis Press themes by adding the following code.

function wp234_featured_post_image($v)  {
    global $post;

	if ( is_singular( 'post' ) && get_post_meta( $post->ID, 'cybocfi_hide_featured_image', true ) ) {
        return ' ';
	}

    return $v;
}
add_filter( 'genesis_pre_get_image', 'wp234_featured_post_image', 8 );

Works great!

Easily control whether the featured image appears in the single post or page view (doesn't hide it in archive/list view).

Markup to Featured Image vs Conditionally display featured image on singular posts and pages