CodeIgniter 4 is the latest version of the framework, intended for use with PHP 7.4+ (including 8.2).
The initial release was February 24, 2020. The current version is v4.3.3.
You *could* download this version of the framework using the button below, but we encourage you to check the Installation section of the User Guide, to use Composer :)
CodeIgniter 3 is the legacy version of the framework, intended for use with PHP 5.6+.
This version is in maintenance, receiving mostly just security updates, and the current version is 3.1.13.