If you're moving a site to Craft from a legacy system like ExpressionEngine, Wordpress, or BigCommerce, you can use Legacy Login to authenticate and migrate your legacy users — seamlessly, without inconveniencing your users unnecessarily.

TL;DR.

Legacy Login plugin provides a way to authenticate users from a legacy system into your Craft CMS site.

The legacy-login/login custom action stands in for Craft's native login form action. If a submitted loginName/password fails Craft's native authentication, the plugin checks the legacy system(s) and tries to authenticate a user from there. If a matching legacy user is found and authenticated, the plugin creates or updates the User in Craft and logs into the newly created/matched account.

What legacy systems are supported?

Legacy Login provides drivers for authenticating legacy users from:

Craft CMS 4.x
Craft CMS 3.x
Craft CMS 2.x
ExpressionEngine 2.x
WordPress

Two legacy drivers are not yet ported to the Craft 4 version of Legacy Login:

BigCommerce (Self-hosted)
Wellspring

Legacy Login

Version 3.0.0

Added

Fixed

Version 3.0.0-beta.2

Fixed

Version 3.0.0-beta.1

Added