Benjamin Intal

This plugin behaves similarly to <a href="https://wordpress.org/plugins/regenerate-thumbnails/" rel="ugc">Regenerate Thumbnails</a> except that images are resized automatically / on the fly, when they are used. Once created, they won’t be processed again.
Your thumbnails will now resize when:
<ul>
<li>Image Sizes in Settings > Media is modified,</li>
<li>Switching themes & plugins with different thumbnail / featured image sizes</li>
</ul>
No settings pages, just install and activate and things should work right away.
Report bugs and help out in the code from the <a href="https://github.com/gambitph/WP-OTF-Regenerate-Thumbnails" rel="nofollow ugc">Github repository</a>
<h4>What are you talking about?</h4>
Test it out. In your normal WordPress website set up, create a gallery using the Add Media button while editing a post or page and use thumbnails. Afterwards, check out your gallery.
Notice the size of your thumbnails, most likely they’re 150 x 150. Do you see it? Great.
Now head over to Settings > Media and change your thumbnail size to something cooler, something rectangular, let’s try 400 x 200. Save it.
Go back to your gallery that you previously created and refresh your browser. Most likely you won’t be seeing 400 x 200 thumbnails there.
OTF Regenerate Thumbnails fixes this for you.
<h4>Usage</h4>
OTF Regenerate Thumbnails should work right away, and your images should get resized when the dimensions get changed.
For developers & tinkerers, ensuring your images get resized properly requires you to use WordPress’ image functions to display featured images and image attachments. Don’t worry, this is a good thing.
Make sure you use these WordPress functions every time you display images:
<ul>
<li><a href="https://codex.wordpress.org/Function_Reference/wp_get_attachment_image_src" rel="nofollow ugc"><code>wp_get_attachment_image_src</code></a></li>
<li><a href="https://codex.wordpress.org/Function_Reference/wp_get_attachment_image" rel="nofollow ugc"><code>wp_get_attachment_image</code></a></li>
<li><a href="https://codex.wordpress.org/Function_Reference/the_post_thumbnail" rel="nofollow ugc"><code>the_post_thumbnail</code></a></li>
<li><a href="https://codex.wordpress.org/Function_Reference/get_the_post_thumbnail" rel="nofollow ugc"><code>get_the_post_thumbnail</code></a></li>
</ul>
You can also add size names using <a href="https://codex.wordpress.org/Function_Reference/add_image_size" rel="nofollow ugc"><code>add_image_size</code></a>
<h4>Features</h4>
<ul>
<li>Creates Resizes thumbnails on the fly</li>
<li>Handles Image Size settings changes in Settings > Media</li>
<li>Handles thumbnail / image size changes introduced by switching themes & plugins</li>
<li>Works automatically, no setup needed</li>
<li>All calls to <code>the_post_thumbnail</code> and other thumbnail functions are handled automatically</li>
<li>Handles image sizes created from <code>add_image_size</code>,</li>
<li>Handles <a href="https://codex.wordpress.org/Function_Reference/the_post_thumbnail" rel="nofollow ugc">2-item array sizes</a></li>
</ul>

OTF Regenerate Thumbnails

Front end - must have

Nice plugin, very useful.
Also works on a network install.
Thanks!



Very useful

Automatically regenerates your thumbnails on the fly when thumbnail sizes change.

Jan Karres

devowl.io GmbH

Matthias Günter

Mario Günter

Faruk Garic

(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


Another freemium plugin that's not even do what it's advertise.Stopped after about 30% of regeneration process, told me to rate the plugin and did not even allowed me to regenerate missing sizes - i need to regenerate all of them.Most of the features are blocked under paywall.That's not the proper way of introducing your product.


Just no

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

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