Shail Mehta

This Plugin is use for create functionality to duplicate any post / all post types, including taxonomies & custom fields
Primary Features 
* Very easy to create duplicate post or duplicate custom post 
* This plugin is free

sm post duplicator

This Plugin is use for create duplicate post or duplicate custom post

Nidhishanker Modi

“WordPress Post Duplicator” provides a feature to duplicate wordpress post type such posts, pages & products.
How to duplicate:
<ol>
<li>Open the page or post you want to duplicate.</li>
<li>In the post listing, there would be button duplicate after view link.</li>
<li>Click on duplicate.</li>
<li>The post will be duplicated and saved as a new post named as (copy) with post title and make it drafted.</li>
<li>System will open Edit duplicated posts.</li>
</ol>

WordPress Post Duplicator

"Wordpress Post Duplicator" provides a feature to duplicate wordpress post type such posts, pages & products.

sm post duplicator vs WordPress Post Duplicator