Migrating users from Joomla to WordPress involves exporting your user database out of Joomla and then importing it into WordPress. While this might sound simple, it can be quite complex depending on the size of your site and whether you’re dealing with just usernames, or also passwords and other data attached to those users.

Two Approaches to Migrating Users from Joomla to WordPress

1. Using a migration plugin
2. Manual migration

One recommended approach, generally the first attempt for many migration engineers, is using an automated migration plugin/tool specifically designed for this purpose. The leading choice, FG Joomla to WordPress Plugin, is a free WordPress plugin that automates the process of migrating your content from Joomla to WordPress including categories, posts, images, and even metadata.

Using the FG Joomla plugin

1. Install and activate the FG Joomla to WordPress plugin.
2. Visit Tools > Import page, then click on ‘Run Importer’ under ‘Joomla (FG)’.
3. Enter your Joomla website details and click on the ‘Test the database connection’ button.
4. Go to Behavior tab and choose options that suit your needs.
5. Click on ‘Start / Resume the import’
6. During importing, do not close your browser until all content including internal links have been imported.

This plugin allows you to migrate categories, posts, images, and users from Joomla to WordPress. However, this might not work seamlessly if you have a large Joomla site or have used many Joomla extensions.

Manual User Migration

The manual process of moving Joomla users to WordPress is bit complex compared to using a plugin but offers more control over what gets transferred over and how it’s set up in the new WordPress site.

1. Export your users’ data from Joomla into an SQL file using phpMyAdmin or similar tools.
2. This SQL file can be imported into your new WordPress database also using phpMyAdmin.
3. Map the field columns between both systems

This method will require some knowledge of MySQL and databases in general.

Do not forget that migrating all users successfully also means moving their passwords which can be challenging since each CMS encodes passwords differently. After successful migration, it may be helpful to force all users to reset their passwords to avoid any potential login issues.

One thing to note that there is no direct method provided by either Joomla or WordPress that allows users to migrate. Also, it is recommended that you take a backup of your websites before beginning the migration process.