Regenerate Post Thumbnails After a WordPress Theme Change

Most WordPress themes these days make use of Post Thumbnails or Featured Images as they are also called – these are one image that you associalte with your blog post which can be used in various sizes around your theme – the size and amount of thumbnails that are set is based on what your theme specifies. If you change to a different theme at a later date you will see that the thumbnail images are distorted – being stretched or compressed depending on the new theme’s sizes.

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Im in the process of moving a blog to a new theme and needed a way to regenerate the thumbnails for the new theme, I found a free plugin which will automate this process called Regenerate Thumbnails, lets take a look at how to use it.

Download Regenerate Thumbnails Here »

Install The Plugin

Download the plugin, then in your WordPress admin, visit “Plugins” > “Add New” > “Upload” and upload the file.

Resize Images

To resize featured images indivually, in your WordPress admin visit “Media” > “Library” and you will see all your uploaded images listed – if you hover over them you will see a “Regenerate Thumbnails” link appear :

On this page, you can also tick the checkboxes next to images and then from the “Bulk Actions” drop down box, again choose “Regenerate Thumbnails” :

Finally, to regenerate all thumbnails on your site at once, visit “Tools” > “Regen Thumbnails” and then click the “Regenerate Thumbnails” button :

The plugin will then start processing all the images and resaving them in the new size specified by your theme. This will take a while if you have a lot of posts, it took around 5 minutes for my site with 100 posts but the plugin does display a percentage progress meter :


This is a nice and simple plugin that does exactly what is required – give it a go next time you change themes and need your thumbnails recreated.

Download Regenerate Thumbnails Here »



Oliver Dale is the founder of Kooc Media, An Internet Company based in Manchester, UK. I founded WPLift and ThemeFurnace, find out more on my Personal Blog. Thanks!

8 thoughts on “Regenerate Post Thumbnails After a WordPress Theme Change”

  1. Hey Oli,
    Have you seen this plugin work across the board? I know I tried it almost a year ago on a Genesis (child) theme that would not cooperate. I gave up on it then. I haven’t tried it since. Thanks for the reminder. I’ll give it another try on some other themes.

  2. Tried Simple Image Sizes plugin on a local installation which didn’t finish the job and found this plugin better Regenerate Thumbnails

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