Clean your Media Library and your Uploads from the files which are not used in your WordPress. Media Cleaner is a very powerful plugin that took many years to perfect. For more information, visit its official page here: Media Cleaner.
The Yearly Standard license is recommended. This license will always work as long as it is active. The lifetime license is, of course, active forever.
If you are a happy user of the free version and want to help us a bit, please contact us.