Konrád Koller

This plugin helps you to fix any missing thumbnail issue in a fairly short time. The only thing you need to do is just few simple click and the plugin does the rest. It can be really helpful if you have thousands of images in your database.
You can regenerate thumbnails for each single image in your database or you can simply select those you really want to update. If you choose a post or page the plugin will regenerate thumbnails for each related images. You can choose from the following methods:
<ul>
<li>Regenerate thumbnails for all images in the database.</li>
<li>Bulk action in post liste: You can choose which one to update by checking the checkboxes.</li>
<li>Media library items: Move your mouse over the chosen image(s) and click on “Regenerate thumbnails” link.</li>
<li>Post editor: click on “Regenerate thumbnails” button which is next to “Add media” button. (Off by default)</li>
</ul>
Furthermore you can add your own thumbnails sizes, change default JPG compression rate and mass regenerate thumbnails. The best thing about this plugin is that you can use it with custom post types as well.

ONet Regenerate Thumbnails

Doesnt have 4.4.1 bulk generation support. But you can generate thumbnails one by one.



Doesnt have 4.4.1 support completely

Fix missing thumbnails in no time with few easy clicks. The plugin does the hard work.

Jordy Meow

When you insert images in WordPress, it’s always a specific image size. It can be an image size such as Medium, Large or something else set by your theme or another plugin. When you update your media sizes settings (or switch theme), you need to regenerate those images (with Regenerate Thumbnails, for example). But what about your posts content? They will be still using the old images, which aren’t actually part of the new metadata, and little by little your WordPress will become more and more broken. This plugin fixes this by regenerating the HTML for your thumbnails / images in your content and keeps everything clean. Once this is done, it’s a good idea to run a tool like Media Cleaner (https://wordpress.org/plugins/media-cleaner/) on your install to detect the useless files.
Be careful!. Before using this plugin, backup your database! It doesn’t modify your files, only database.

Regenerate Thumbnails HTML

Works well on my two plugins after switching to a new theme. Regenerate Thumbnails (after set up the new sizes) + Regenerate Thumbnails HTML (on all posts, for 2 or 3 sizes) + Media Cleaner (to delete the useless files). In one hour, the new installs are neat and clean.

It works well

Thank you!
After change WP media sizes for new theme we must use regenerate thumbnail plug-in. But I want apply new sizes in old post! After that I can clear old images!

Good work with "view-broken-links" plug-in.

Gold in ocean of wp problems

Update the HTML of the images contained in the post from one image size to another. Useful when switching between sizes and themes.

ONet Regenerate Thumbnails vs Regenerate Thumbnails HTML