lucia.intelisano

If post doesn’t have a set featured image, 
WP Autoset Featured Image Plus check if text contains an image. If yes, set this as featured image, 
if not, you can set any external url image. Otherwise, leave field empty. 
Easy and fast!
Features include:

WP Autoset Featured Image Plus

Check for an image inside text editor or use external images from anywhere as the featured image of your pages and posts.

toannth

Requires at least: 4.4 
Tested up to: 4.9 
Stable tag: 1.0.0 
License: GNU General Public License v2 or later 
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Resizes WordPress images on the fly using Nginx Image-Filter.

Ngx Image Resizer

Requires at least: 4.4 Tested up to: 4.9 Stable tag: 1.0.0 License: GNU General Public License v2 or later License URI: http://www.gnu.

WP Autoset Featured Image Plus vs Ngx Image Resizer