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.

Orangelab

Rickard Westerlind

Dramatically improve the quality of re-sized images by making WordPress use ImageMagick instead of standard GD image library.
Features
<ul>
<li>Preserve embedded color profile in re-sized image</li>
<li>Automatically recognize custom image sizes</li>
<li>Allow regeneration of existing images (optionally for selected image sizes only)</li>
<li>Configure image quality or use dynamically computed default value</li>
<li>Optimize different image sizes for either quality or size</li>
</ul>
Lnguages: English, French, German, Swedish, Turkish
Requires either ImageMagick binary or Imagick PHP module.
<h3>Contribute</h3>
Code repo available on https://github.com/orangelabweb/imagemagick-engine/

ImageMagick Engine

Maybe even better.  It uses ImageMagick Engine that is installed and allows me to easily regenerate all my images.

Works as advertised

The thumbnail regeneration could be a bit faster though. I have used it for longer than I can remember, at least 5 years.

Simple, functional

Improve the quality of re-sized images by replacing standard GD library with ImageMagick.

Regenerate Thumbnails HTML vs ImageMagick Engine