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.

Stephanie Leary

This is a utility for converting lots of posts or pages to a custom post type (or vice versa). You can limit the conversion to posts in a single category or children of specific page. You can also assign new taxonomy terms, which will be added to the posts’ existing terms.
This plugin is useful for converting many posts at once. If you’d rather do one at a time, use <a href="https://wordpress.org/extend/plugins/post-type-switcher/" rel="ugc">Post Type Switcher</a> instead.

Convert Post Types

Wordpress 4.9.5

No better plugin for converting categories to custom post types. And vice versa.

Still works great

A bulk conversion utility for post types.

Post Type Convertr vs Convert Post Types