How to know CodeIgniter Version

To know the current version of CodeIgniter you are using, you just need to echo a constant.

<?php echo CI_VERSION; ?>

Another way to know the version of CodeIgniter is to check it manually in the file where the constant CI_VERSION is declared.

The constant CI_VERSION is declared in :

system/core/CodeIgniter.php

You can check it there as well if you don’t prefer or like the first option.