CodeIgniter has two supported installation methods: manual download, or using Composer. Which is right for you?

  • We recommend the Composer installation because it keeps CodeIgniter up to date easily.

  • If you would like the simple “download & go” install that CodeIgniter 3 is known for, choose the manual installation.

However you choose to install and run CodeIgniter4, the latest user guide is accessible online. If you want to see previous versions, you can download from the codeigniter4/userguide repository.


Before using CodeIgniter 4, make sure that your server meets the requirements, in particular the PHP version and the PHP extensions that are needed. You may find that you have to uncomment the php.ini “extension” lines to enable “curl” and “intl”, for instance.