Benjamin Intal

<p>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.</p>
<p>Your thumbnails will now resize when:</p>
<ul>
<li>Image Sizes in <strong>Settings > Media</strong> is modified,</li>
<li>Switching themes & plugins with different thumbnail / featured image sizes</li>
</ul>
<p>No settings pages, just install and activate and things should work right away.</p>
<p>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></p>
<h4>What are you talking about?</h4>
<p>Test it out. In your normal WordPress website set up, create a gallery using the <strong>Add Media</strong> button while editing a post or page and use thumbnails. Afterwards, check out your gallery.</p>
<p>Notice the size of your thumbnails, most likely they’re <strong>150 x 150</strong>. Do you see it? Great.</p>
<p>Now head over to <strong>Settings > Media</strong> and change your thumbnail size to something cooler, something rectangular, let’s try <strong>400 x 200</strong>. Save it.</p>
<p>Go back to your gallery that you previously created and refresh your browser. Most likely you <em>won’t</em> be seeing <strong>400 x 200</strong> thumbnails there.</p>
<p>OTF Regenerate Thumbnails fixes this for you.</p>
<h4>Usage</h4>
<p>OTF Regenerate Thumbnails should work right away, and your images should get resized when the dimensions get changed.</p>
<p><strong>For developers & tinkerers, ensuring your images get resized properly requires you to use WordPress’ image functions to display featured images and image attachments.</strong> Don’t worry, this is a good thing.</p>
<p>Make sure you use these WordPress functions <strong>every time you display images</strong>:</p>
<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>
<p>You can also add size <em>names</em> using <a href="https://codex.wordpress.org/Function_Reference/add_image_size" rel="nofollow ugc"><code>add_image_size</code></a></p>
<h4>Features</h4>
<ul>
<li>Creates Resizes thumbnails on the fly</li>
<li>Handles Image Size settings changes in <strong>Settings > Media</strong></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.

Adi Glibanović

<p>The Selective Thumbnail Regenerator plugin provides a convenient way to regenerate image thumbnails for WordPress media libraries. Unlike other thumbnail regeneration plugins that process the entire library, this plugin allows you to selectively regenerate thumbnails for images uploaded during a specific year and month.</p>
<h4>Key Features</h4>
<ul>
<li><strong>Date-based Selection</strong>: Choose a specific year and month to limit which thumbnails are regenerated</li>
<li><strong>Progress Tracking</strong>: Visual progress bar shows the status of the regeneration process</li>
<li><strong>User-friendly Interface</strong>: Simple dropdown menu interface for date selection</li>
<li><strong>Resource-friendly</strong>: Built-in delay between each regeneration to prevent server overload</li>
<li><strong>Real-time Updates</strong>: Status messages show the current progress and any errors</li>
</ul>
<h3>Usage</h3>
<ol>
<li>In your WordPress admin panel, navigate to Tools > Selective Thumbnail Regenerator.</li>
<li>Select the year and optionally the month for which you want to regenerate thumbnails.</li>
<li>Click “Check Number of Images” to see how many images will be processed.</li>
<li>Click “Regenerate Thumbnails” to start the regeneration process.</li>
<li>Wait for the process to complete – you’ll see a progress bar and status updates.</li>
</ol>
<h3>Troubleshooting</h3>
<h4>Error: “No images found for the selected period”</h4>
<p>This means there are no images in your media library that were uploaded during the selected year and month. Try selecting a different time period.</p>
<h4>The regeneration process is slow</h4>
<p>This is normal behavior. The plugin deliberately adds a 1-second delay between processing each image to prevent server overload. This might make the process seem slow, but it ensures stability.</p>
<h4>The process stops with an error message</h4>
<p>If you encounter an error during regeneration, check your server’s PHP error logs for more details. Common issues include memory limits, timeout settings, or file permission problems.</p>


Selective Thumbnail Regenerator

A WordPress plugin that allows users to regenerate thumbnails for media files uploaded in specific months and years.

OTF Regenerate Thumbnails vs Selective Thumbnail Regenerator