What is CodeIgniter 4
CodeIgniter is an application development framework, a set of tools, for people who create websites using PHP. Its goal is to allow you to develop projects much faster than you could if you were writing code from scratch, providing a rich set of libraries for commonly needed tasks, as well as a simple interface and logical structure for accessing these libraries.
Click the below link to download CodeIgniter 4 from official site
Download the latest version, and extract it.
Configuration & Set Up
Step 1: Open the app/Config/App.php file with a text editor and set your base URL.
Step 2: open the app/Config/Database.php file with a text editor and set your database settings.
you can run project using serve command open command window and in project root directory paste following command to run project
php spark serve
Once you execute above command you will see the URL like this http://localhost:8080 open this in the browser and done your CodeIgniter 4 Installation.
Problem if you are facing
PHP Fatal error: Uncaught Error: Call to undefined function CodeIgniter\locale_
set_default() in C:\xampp\htdocs\framework-4.0.4\system\CodeIgniter.php:184
Open PHP.ini file enable ;extension=intl
then you will not face any problem for installing CodeIgniter 4