Manual Installation

The CodeIgniter 4 framework repository holds the released versions of the framework. It is intended for developers who do not wish to use Composer.

Develop your app inside the app folder, and the public folder will be your public-facing document root. Do not change anything inside the system folder!


This is the installation technique closest to that described for CodeIgniter 3.


Download the latest version, and extract it to become your project root.


Before v4.4.0, CodeIgniter autoloader did not allow special characters that are illegal in filenames on certain operating systems. The symbols that can be used are /, _, ., :, \ and space. So if you installed CodeIgniter under the folder that contains the special characters like (, ), etc., CodeIgniter didn’t work. Since v4.4.0, this restriction has been removed.

Initial Configuration

After installation, a few initial configurations are required. See Initial Configuration for the detail.


Download a new copy of the framework, and then replace the system folder.

Read the upgrade instructions and change log, and check Breaking Changes and Enhancements.


Download and run.


You need to check for file changes in the project space (root, app, public, tests, writable) and merge them by yourself.


Folders in your project after set up:

  • app, public, tests, writable, system

Translations Installation

If you want to take advantage of the system message translations, they can be added to your project in a similar fashion.

Download the latest version of them. Extract the downloaded zip, and copy the Language folder contents in it to your app/Languages folder.

This would need to be repeated to incorporate any updates to the translations.