Add Featured Image To WP RSS Feed

add-features-image-to-wordpress-rss-feed

<?php
//This will prepend your WordPress RSS feed content with the featured image
function wbd_featured_image_in_rss_feed( $content ) {
  global $post;
  if( is_feed() ) {
    if ( has_post_thumbnail( $post->ID ) ){
      $prepend = '<div>' . get_the_post_thumbnail( $post->ID, 'medium', array( 'style' => 'margin-bottom: 10px;' ) ) . '</div>';
      $content = $prepend . $content;
    }
  }
  return $content;
}
add_filter('the_content', 'wbd_featured_image_in_rss_feed'); 
add_filter('the_excerpt_rss', 'wbd_featured_image_in_rss_feed');
add_filter('the_content_feed', 'wbd_featured_image_in_rss_feed');

Add this to your theme's functions.php file