RustyBadRobot

Rusty Social Image Share resizes your post thumbnail to perfectly fit to the Facebook Share dimensions whilst keeping your original image dimensions.
See the <a href="https://wordpress.org/extend/plugins/rusty-image-share/screenshots/" rel="ugc">screenshots tab</a> for more details.

Rusty Social Image Share

Keep your original Featured Image proportions whilst sharing to Facebook.

Stanislav Khromov

This plugin enables upscaling of thumbnails for small media attachments. The default behaviour of WordPress is to not upscale small images, which means 
you are never guaranteed a certain size for a thumbnail format. This plugin corrects that and upscales small images to the specified thumbnail dimensions. 
This is beneficial in grid layouts where images of different sizes can make the grid malfunction.
<a href="https://wordpress.org/plugins/thumbnail-upscale/screenshots/" rel="ugc">Check screenshots for an example!</a>
Important: Your thumbnails format must have the crop setting enabled to be processed by this plugin.
Usage
After you have enabled Thumbnail Upscale plugin, all your future uploaded images will be upscaled. 
For existing images, install and run <a href="https://wordpress.org/plugins/force-regenerate-thumbnails/" rel="ugc">Force Regenerate Thumbnails</a> 
This will upscale your existing media images!
<h3>Requirements</h3>
<ul>
<li>PHP 5.2 or higher strongly recommended</li>
</ul>
<h3>Translations</h3>
None. The plugin has no translateable strings.

Thumbnail Upscale

Whaaaaat? You don't use this plugin? It's good.

It’s still relevant god damn it

Enables upscaling of thumbnails for small media attachments

Rusty Social Image Share vs Thumbnail Upscale