Antonio D.

Daniil Zhitnitskii

With use of this plugin you will not longer need to care about clean state of your database because of plenty of revisions. Once the plugin is activated, every time you visit admin dashboard of a site it will automatically detect revisions, which are older then you need, and flush them from database.
Only works with multisite installation!
<h3>Disclaimers</h3>
The Simple Revision Cleaner plugin is supplied “as is” and all use is at your own risk.

Simple Revision Cleaner

This plugin provides simple handy tool for automatic cleaning database from old, non-relevant revisions on your web-site.

thaikolja

Thumbnails Cleaner helps you keep your WordPress installation tidy by removing and regenerating thumbnails.
You can control all functions through the plugins’ main page found under “Tools”. You can:
<ul>
<li>Analyze your uploads directory, giving you an overview how many original files and thumbnails there are.</li>
<li>Clean thumbnails which means deleting them while keeping the original files.</li>
<li>Restore thumbnails to start out with a clean uploads directory. This function requires the plugin <a href="https://wordpress.org/plugins/regenerate-thumbnails/" rel="ugc">Regenerate Thumbnails</a>.</li>
<li>Create backups of your uploads directory to keep your files safe in the unlikely event that there is a problem.</li>
<li>Restore backups in case you have lost a file that was not supposed to be deleted.</li>
</ul>
Please see the <a href="https://www.koljanolte.com/wordpress/plugins/thumbnail-cleaner/documentation/" rel="nofollow ugc">official website</a> for a full 
documentation.

Thumbnail Cleaner

Cleans up your WordPress installation by removing and regenerating thumbnails.

Simple Revision Cleaner vs Thumbnail Cleaner