Welcome to CodeIgniter4
CodeIgniter is a PHP full-stack web framework that is light, fast, flexible and secure.
It is an Application Development Framework - a toolkit - for people who build web sites using PHP. Its goal is to enable you to develop projects much faster than you could if you were writing code from scratch, by providing a rich set of libraries for commonly needed tasks, as well as a simple interface and logical structure to access these libraries.
CodeIgniter lets you creatively focus on your project by minimizing the amount of code needed for a given task.
Where possible, CodeIgniter has been kept as flexible as possible, allowing you to work in the way you want, not being forced into working any certain way. The framework can have core parts easily extended or completely replaced to make the system work the way you need it to.
In short, CodeIgniter is the malleable framework that tries to provide the tools you need while staying out of the way.
Is CodeIgniter Right for You?
CodeIgniter is right for you if:
You want a framework with a small footprint.
You need exceptional performance.
You want a framework that incorporates a number of features and techniques to enable you to do good security practices easily.
You want a non-magical framework that you can easily find and read the source code.
You want a framework that requires nearly zero configuration.
You want a framework that does not require you to adhere to restrictive coding rules.
You want a framework that makes it easy to create test code.
You do not want to be forced to learn a templating language (although a template parser is optionally available if you desire one).
You eschew complexity, favoring simple solutions.
You need clear, thorough documentation.