Nico

<a href="http://nextgenthemes.com/plugins/regenerate-thumbnails-reminder/" rel="nofollow ugc">Plugin Page</a>
A small reminder in your admin area every time a image setting was changed (in media options, through a theme or plugin)
You most likely want to regenerate the thumbnails after this plugin reminds you to do so, if not already done I suggest you install the most used plugin Regenerate Thumbnails for this. This plugin will offer a redirection to <a href="https://wordpress.org/plugins/regenerate-thumbnails/" rel="ugc">Regenerate Thumbnails</a> in the admins reminder notice, but you can use any other plugin/method you prefer to regenerate thumbnails, just click dismiss when the reminder shows up and then manually navigate to your preferred regenerate plugin.

Regenerate Thumbnails Reminder

Checks if your image sizes have changed or if there was a new one added, if so it reminds you to go regenerate them.

Mario Günter

Faruk Garic

devowl.io GmbH

Matthias Günter

Jan Karres

(Re)generate single or multiple image sizes for your WordPress website and create a SEO-optimised custom structure for uploading thumbnails.
Regenerate UNLIMITED thumbnails with the free version!
In the course of optimising a WordPress website, it can often be necessary to change the theme – especially if the website is still being created. Unfortunately, a theme change can alter the image sizes and lead to despair. This is where Real Thumbnail Generator comes into play: The WordPress plugin is responsible for regenerating the image sizes. With a few clicks, the problem is solved! This way, themes can be changed as often as desired without negatively affecting the media management.
<h3>Free Sandbox</h3>
You want to try WordPress Real Thumbnail Generator before 
installing? Take a free sandbox and play around!
<a href="https://try.devowl.io/?product=RTG" rel="nofollow ugc">Create sandbox</a>
<h3>Features</h3>
Some of the features listed below are only available in the <a href="https://devowl.io/go/real-thumbnail-generator?source=wordpress-org-description" rel="nofollow ugc">PRO version of Real Thumbnail Generator</a>. They are marked with an asterisk.
<ul>
<li>Mass regeneration of thumbnails in the media library</li>
<li>Regenerating individual images in the media library</li>
<li>Works great with PDF files (<a href="https://devowl.io/knowledge-base/wordpress-pdf-thumbnails-not-generated/" rel="nofollow ugc">note requirements</a>)</li>
<li>Skip already existing thumbnails *</li>
<li>
Detection and deletion of unused image sizes *
</li>
<li>
Reliable and fast regeneration of thumbnails (without aborts as known from other plugins)
</li>
<li>Compatible with all major themes and many plugins</li>
<li>Custom upload structure for thumbnail paths and file names *</li>
<li>
Supports WordPress Multisite
</li>
<li>
One-time payment with lifetime updates
</li>
<li>Fast support from Germany</li>
<li>DSGVO/GPDR: The plugin does not collect any personal data without your consent!</li>
</ul>
<h3>Compatibility</h3>
Real Thumbnail Generator is compatible with all common themes and plugins.

Real Thumbnail Generator: Efficient regeneration of thumbnails in all sizes

Great and up to date

Real Thumbnail Generator is a WordPress plugin for regenerating thumbnails. It is beginner-friendly, SEO-optimised and GDPR-compliant.

Regenerate Thumbnails Reminder vs Real Thumbnail Generator: Efficient regeneration of thumbnails in all sizes