Pete

Note: Obsolete since WordPress 4.4
<a href="https://core.trac.wordpress.org/ticket/32230" rel="nofollow ugc">This feature has been added into the core of WordPress 4.4</a>. You can now export your attachments by going to Tools->Export and select ‘Media’ as the export type.
Original Description
WP Attachment Export allows you to export your media library into a WordPress eXtended RSS or WXR file. You can then use the Tools->Import function in another WordPress installation to import the media library.
<h4>Issues / Bug reporting</h4>
Found a bug? Please use the issue tracker at <a href="https://github.com/thehelvetian/wp-attachment-export/issues" rel="nofollow ugc">https://github.com/thehelvetian/wp-attachment-export/issues</a>
<h3>Usage</h3>
User <a href="https://wordpress.org/support/profile/philho" rel="ugc">PhiLho</a> has put together a good summary on how to use the plugin at <a href="https://wordpress.org/support/topic/good-but-could-use-more-explanations" rel="ugc">https://wordpress.org/support/topic/good-but-could-use-more-explanations</a>. Thanks PhiLho!

WP Attachment Export

works perfectly.

Exports only posts of type 'attachment', i.e. your media library

Ben Byrne

kenjigarland

Xavier Serrano

Media Deduper will find and eliminate duplicate images and attachments from your WordPress media library. After installing, you’ll have a new “Manage Duplicates” option in your Media section.
Before Media Deduper can identify duplicate assets, it will build an index of all the files in your media library, which can take some time. Once that’s done, however, Media Deduper automatically adds new uploads to its index, so you shouldn’t have to generate the index again.
Need faster indexing? <a href="https://www.mediadeduper.com/" rel="nofollow ugc">Check out Media Deduper Pro</a>.
Once up and running, Media Deduper provides you with a “Manage Duplicates” page listing all of your duplicate media files. The list makes it easy to see and delete duplicate files: delete one and its twin will disappear from the list because it’s then no longer a duplicate. Easy! By default, the list is sorted by file size, so you can focus on deleting the files that will free up the most space.
Use this plugin at your own risk. The plugin developers are not responsible for any lost data or site issues as a result of using this plugin.
Media Deduper comes with a “Smart Delete” option that prevents a post’s Featured Image from being deleted, even if that image is found to be a duplicate elsewhere on the site.
If a post has a featured image that’s a duplicate file, Smart Delete will re-assign that post’s image to an already-in-use copy of the image before deleting the duplicate so that the post’s appearance is unaffected. This feature only tracks Featured Images, and not images used in galleries, post bodies, shortcodes, meta fields, or anywhere else.
Looking for more features? <a href="https://www.mediadeduper.com/" rel="nofollow ugc">Media Deduper Pro</a> includes features for image fields from several popular plugins as well.
Note that duplicate identification is based on the data of the files themselves, not any titles, captions or other metadata you may have provided in the WordPress admin.
Media Deduper can differentiate between 1.) media items that are duplicates because the media files they link to have the same data and 2.) those that actually point to the same data file, which can happen with a plugin like WP Job Manager or Duplicate Post.
As with any plugin that can perform destructive operations on your database and/or files, using Media Deduper can result in permanent data loss if you’re not careful. Back up your data before you try out Media Deduper! Please!
Use this plugin at your own risk. The plugin developers are not responsible for any lost data or site issues as a result of using this plugin.
Need more support? <a href="https://www.mediadeduper.com/" rel="nofollow ugc">Media Deduper Pro</a> includes dedicated support from Cornershop Creative.
<h3>Requirements</h3>
Media Deduper requires PHP 7.0 or later.

Media Deduper

Save disk space and bring some order to the chaos of your media library by removing and preventing duplicate files.

WP Attachment Export vs Media Deduper