Add or Change Content in the Featured Image Meta Box

Perhaps you need to provide a little extra instruction about the Featured Image meta box. It doesn’t take much to add your own text to that box:

add_filter( 'admin_post_thumbnail_html', 'add_featured_image_instruction');
function add_featured_image_instruction( $content ) {
    return $content .= '<p>The Featured Image is an image that is chosen as the representative image for Posts or Pages. Click the link above to add or change the image for this post. </p>';

Add Featured Image Thumbnail to Posts Page

Customize the information that is displayed on the ‘posts’ page

Adding a column labeled “Thumbnail” (and delete the “Comments” column).

add_filter( 'manage_edit-post_columns', 'set_columns' );
function set_columns($columns) {
	$columns['thumbnail'] = 'Thumbnail';
	unset( $columns['comments'] );
	return $columns;

Now we need to tell WordPress what to do with this new “Thumbnail” space. Here, we’re checking for the existence of a featured image and displaying it, or noting that there is no thumbnail.

add_action( 'manage_posts_custom_column', 'fill_columns' );
function fill_columns($column) {
	global $post;
	switch($column) {
		case 'thumbnail' :
			if (has_post_thumbnail($post->ID))
				echo get_the_post_thumbnail($post->ID, array(50, 50));
				echo '<em>no thumbnail</em>';

Remove Title Attribute from Featured Image

If you have featured images (formerly post thumbnails) that aren’t named as well as they could be, it’s nice to remove the title attribute so that things like “header-large” don’t appear in the tool tips.

add_filter('post_thumbnail_html', 'remove_feat_img_title');
function remove_feat_img_title($img) {
    $img = preg_replace('/title="(.*?)"/','',$img);
    return $img;