In a recent project for a client, I needed to convert all the posts to a new Video custom post type that I built for the site. Since the site is growing and contains lots of video, I believe that using custom post type will make it easier for the client to manage his posts by separating the normal articles from the video posts.
Enter Convert Post Types plugin.
As the name suggests, this plugin helps you to convert normal post or page to any custom post type and vice versa. Interestingly, it also supports custom taxonomies.
Additionally, you can limit the conversion to posts in a single category or children of a specific page. Prior to converting the posts, you can assign the new custom post type or custom taxonomy to the posts.
This plugin helps you to convert the posts in bulk. For example, if you’d like to convert all posts in Category 1 to Album taxonomy, that can be done in few clicks.
Alternatively, if you’d rather convert one post at a time, take a look at Post Type Switcherplugin. This plugin also now supports converting posts in bulk.