There may come a time when you want to move Joomla articles into a WordPress blog or vice-versa. Alternatively, content can easily be moved between the big 3; Joomla, WordPress and Drupal.
The procedure is very simple to move a single page or few pages.
To move the content,
1) Open up the editor in HTML or source mode
2) Select all
4) Paste into HTML or Source code into the editor of choice.
Option A: Plugin
Find a WordPress plugin that will do this for you; such as FG Joomla to WordPress.
Build a Custom PHP / mySQL Script
If you have many pages that need to be moved, you can export any pages, categories and sections that you want with phpMyAdmin. Then, create a new table with phpmyadmin and dump the desired files into an sql file. Now, you just need to match the tables up with your WordPress Installation; while leaving the autoincrement field blank. Once the tables are the same, you can export it and import it into WordPress.
Alternatively, you can create a custom php / mySQL script which will select the data you want from your Joomla database and insert it into your WordPress database. When you run the insert command, you can use the Joomla content and page name for the WordPress post_title, and post_name. The guid can be inserted using the the last_inserted_id() function for which you append the id onto the appropriate guid string. Then, you add what is appropriate into the other fields; such as dates, post_author and post_parent.