Priyanka Bhave

This plugin provides functionality to duplicate the post, pages and the CPT’s with all the custom attributes like taxonomies and post meta data.
How to duplicate the posts, pages or CPT’s :
<ol>
<li>Open the posts, page or CPT on click of the menu from the left menu of dashboard.</li>
<li>Click on the duplicate link display in the post title, on hover of the title name.</li>
</ol>

WP Duplicate posts pages & CPT

Duplicate posts, pages and CPT with all custom data.

voceplatforms

Jeff Stieler

Kevin Langley Jr.

Adds meta boxes to all post types and allows you to convert the post type of the current post you are editing to a different post type. This very useful when doing an import from another site into one post type that then needs to be filtered into different post types or even to fill dummy posts throughout multiple post types.
Please refer to full documentation at https://github.com/voceconnect/post-type-converter/wiki.

Post Type Converter

Allows you to convert the post type of objects while in the edit screen.

WP Duplicate posts pages & CPT vs Post Type Converter