Every wordpress theme has different thumbnail sizes. By default wordpress create multiple resized images. By default wordpress create four resized images. Means when we upload image, wordpress upload five images on server. Which is not necessary and unwanted. If your theme added, custom thumbnail sizes then it create more than five images and upload on server.
Why regenerate thumbnails in wordpress is important
Due to custom thumbnail sizes your server images data will always increase. So Whenever you use new wordpress theme, regenerate thumbnails in wordpress as per your theme UI. After changing wordpress theme. sometimes you don’t found old images for using as featured image or thumbnail. Because in new theme, default thumbnail size would be overridden through code. So regenerating thumbnail images is always important whenever you change the wordpress theme.
how regenerate thumbnails in wordpress
I found nice wordpress plugin which will delete unnecessary images from server and regenerate thumbnail images as per your theme requirement and design. This plugin will delete unwanted images from server or your site and save your disk space. This plugin is very great when you are using shared hosting or small server.
Force Regenerate Thumbnails (https://wordpress.org/plugins/force-regenerate-thumbnails/)
Admin panel of Force regenerate thumbnail plugin
regenerate thumbnails in wordpress. Delete and REALLY force the regenerate thumbnail.
Force Regenerate Thumbnails allows you to delete all old images size and REALLY regenerate the thumbnails for your image attachments.
I personally used force regenerate thumbnail plugin. Earlier on my server there are more than 4 thousand images were uploaded but I found more than 25 thousand images on server (in uploads folder). After using regenerating images there are only 12 thousand images were created by this plugin. I really found useful this plugin. it saved my disk space and deleted the unwanted images.
There are other plugins which regenerate the thumbnail but they never delete the unwanted images from server. Only bad thing about this plugin is, It does not optimize images with regeneration of plugin. I will write about optimizing uploaded images in next article.