Deleting Unused Thumbnails

By default, WordPress generates thumbnails for all registered sizes, the challenge we are facing is that we do not want the multiple thumbnail sizes to be generated for images embedded/inserted within the post content.

These images are basically not featured images but their various registered sizes are still generated during the upload process and then obviously stored on our storage media. These variants are of no use to us (or anyone, we guess) but occupy file count and storage space.

So what’s actually required is to force regenerate the thumbnails for only featured images and delete the various sizes generated for the images which are inserted/embedded within the post content.

Eg. Let’s say the WordPress and the active theme in use have 10 image sizes registered in total. Now, if we create a post with an image gallery, the no. of images will be:

1 Featured Image + 10 Sizes Generated = 11 Images
10 Images Inserted In Gallery + 100 Image Sizes Generated = 110 Images
The total for one such post becomes 11 + 110 = 121 thumbnails.

These extra sizes for image gallery uploads are not required, and that can reduce the image count by 100, making it 21 images only for these types of posts that use image galleries within them.

Since most of our posts use this format, is there any way to get rid of these extra thumbnails?

This will help in significantly reducing the number of files on the server, else it is going to increase at an enormous rate as we scale up further.

Sorry for the long post ??