Stefano Lissa

WordPress themes need thumbnails in different sizes and they even let the user to change those dimensions. 
But WordPress has a problem: it does not regenerates the thumbnails when new sizes are registered.
Thumbnails intercepts the request by themes or plugins to WordPress to get a specific thumbnail, generates it and caches it on disk. 
Efficiently, it produces a perfectly cropped image, with the right dimension avoiding unpleasant stretching.
Thumbnails does not modify your blog or your media library. When deactivated the blog returns to its old behavior.
The second important feature is the autoselection of featured image for post which are missing it. 
You can choose between the on the fly selection without persist it or, for better performances, to persist it once selected.
Read the <a href="https://www.satollo.net/plugins/thumbnails" rel="nofollow ugc">Thumbnails</a> official page for detailed information.
Theme developers can find instructions to use it (no code tied to Thumbnails needs to be written!).
Other plugins by Stefano Lissa:
<ul>
<li><a href="https://www.satollo.net/plugins/hyper-cache" rel="nofollow ugc">Hyper Cache</a></li>
<li><a href="https://www.thenewsletterplugin.com" rel="nofollow ugc">Newsletter</a></li>
<li><a href="https://www.satollo.net/plugins/header-footer" rel="nofollow ugc">Header and Footer</a></li>
<li><a href="https://www.satollo.net/plugins/include-me" rel="nofollow ugc">Include Me</a></li>
<li><a href="https://www.satollo.net/plugins/ads-bbpress" rel="nofollow ugc">Ads for bbPress</a></li>
</ul>
<h3>Screen shots</h3>
No screenshots are available at this time.

Thumbnails

This plugin solves my problems with the WP thumbnails, thanks Stefano!

The one that solves my problem

I re-use my post thumbnail images in various ways, so I like to upload them full size, and I need the software to resize them as needed. This plugin does exactly that for me.

It performs its magic transparently and makes my pages a lot lighter. Highly recommended.


Amazing

Autoselect the featured image and creates pixel perfect resizes on the fly without regenerate all the thumbnails.

Alex Mills

Regenerate Thumbnails allows you to regenerate all thumbnail sizes for one or more images that have been uploaded to your Media Library.
This is useful for situations such as:
<ul>
<li>A new thumbnail size has been added and you want past uploads to have a thumbnail in that size.</li>
<li>You’ve changed the dimensions of an existing thumbnail size, for example via Settings â Media.</li>
<li>You’ve switched to a new WordPress theme that uses featured images of a different size.</li>
</ul>
It also offers the ability to delete old, unused thumbnails in order to free up server space.
<h4>In Memory of Alex Mills</h4>
In February 2019 Alex Mills, the author of this plugin, <a href="https://alex.blog/2019/02/27/from-alexs-family/" rel="nofollow ugc">passed away</a>. He leaves behind a number of plugins which will be maintained by Automattic and members of the WordPress community. If this plugin is useful to you please consider donating to the Oregon Health and Science University. You can find more information <a href="https://alex.blog/2019/03/13/in-memory-of-alex-donation-link-update/" rel="nofollow ugc">here</a>.
<h4>Alternatives</h4>
WP-CLI
If you have command line access to your server, I highly recommend using <a href="https://wp-cli.org/" rel="nofollow ugc">WP-CLI</a> instead of this plugin as it’s faster (no HTTP requests overhead) and can be run inside of a <code>screen</code> for those with many thumbnails. For details, see the documentation of its <a href="https://developer.wordpress.org/cli/commands/media/regenerate/" rel="nofollow ugc"><code>media regenerate</code> command</a>.
Jetpack’s Photon Module
<a href="https://jetpack.com/" rel="nofollow ugc">Jetpack</a> is a plugin by Automattic, makers of WordPress.com. It gives your self-hosted WordPress site some of the functionality that is available to WordPress.com-hosted sites.
<a href="https://jetpack.com/support/photon/" rel="nofollow ugc">The Photon module</a> makes the images on your site be served from WordPress.com’s global content delivery network (CDN) which should speed up the loading of images. Importantly though it can create thumbnails on the fly which means you’ll never need to use this plugin.
I personally use Photon on my own website.
Disclaimer: I work for Automattic but I would recommend Photon even if I didn’t.
<h4>Need Help? Found A Bug? Want To Contribute Code?</h4>
Support for this plugin is provided via the <a href="https://wordpress.org/support/plugin/regenerate-thumbnails" rel="ugc">WordPress.org forums</a>.
The source code for this plugin is available on <a href="https://github.com/automattic/regenerate-thumbnails" rel="nofollow ugc">GitHub</a>.

Regenerate Thumbnails

I'm a longtime WP dev and if you need to regenerate thumbnails its the way to go.

I appreciate the fact its free, this is what makes WP great

5 Stars


I can't even remember for how long I've been using this plugin from time to time... Miss you Alex... I'm sure you're smiling from up above 3> 


Thanks, Alex...

Regenerate the thumbnails for one or more of your image uploads. Useful when changing their sizes or your theme.

Thumbnails vs Regenerate Thumbnails