Dues to the various reasons, you might need to clean up your Media Library in WordPress website and remove all unused images. Those are usually images that were uploaded in some posts as post content images or ex-featured images from deleted posts.
How to delete unused images automatically?
You can automatically remove all unused images using the plugin. There is a plugin here, called Media Cleaner and it’s available for free download.
You can also install this plugin from your WordPress dashboard, just access the WordPress admin -> Plugins -> Add new. Here just type the Media Cleaner in the search field at the right side.
(*) It’s always advisable that before running such plugin, you make the fresh backup of your website in case something went wrong.
Now, click install and activate the plugin.
Removing images with Media Cleaner plugin
Access the plugin Media Cleaner in WordPress admin -> Meow Apps -> Media Cleaner.
You will see the options available for the free version that is enough for cleaning any orphaned images or images from the deleted posts. All of the plugin features and options are basic and we won’t explain them one by one in this quick review.
The plugin will scan the base and match the available images with the posts image attachments. If everything is fine, you should deflate the disk usage very fast.
Other plugins for deleting unused images from WordPress Media Library
You should also check up a slightly newer plugin WPS Cleaner, which takes care of more than just unused and obsolete images.
The plugins should deal with the problem of removing old and unused images from your WordPress website media library.
If you stumble upon anything specific, please use the comment form to ask for help or advice.