Mario Peshev

Delete all Custom Field entries assigned to posts that do not exist in the posts table.
Navigate to Settings -> Remove Unused CFs and delete all postmeta for non-existing posts.

DX Remove Unused Custom Fields

Does exactly what it says.
Installed, navigate to the settings page, click "Delete" and Done! Cannot be easier than that.
Thank you!



Simply Awesome!

Delete the Custom Fields from your postmeta table where assigned posts no longer exist.

Sanam Maharjan

This is a plugin for converting lots of posts or pages to a custom post type (or vice versa). In the ‘convert from…’ select option you will get the lists of all the post types stores in your current database and in the ‘convert to…’ option you will get the list of all the current registered post types. In addition to this you can also convert from one taxonomy to another and the lists are populated just as that of post types.

Post Type Convertr

A bulk conversion utility for post types and taxonomies.

DX Remove Unused Custom Fields vs Post Type Convertr