Difference Between CodeIgniter3 and CodeIgniter4

Difference Between CodeIgniter3 and CodeIgniter4

CodeIgniter is a PHP Framework, It is based on an MVC design pattern. MVC stands for Model, View, Controller It is a very trending design pattern of programming. CodeIgniter has a lot of features that reduce our code as compared to core PHP code.

Model: this contains database-related codes.

View: this contains design files such as index, contact, about pages, etc.

Controller: it acts as an intermediate between model and view. It contains logic.

In this blog, we will learn the difference between CodeIgniter3 and CodeIgniter4. Codeigniter3 has a lot of features for web developers but now codeigniter4 has been launched, CodeIgniter4 comes up with good performance as compared to CodeIgniter3.

Let’s see the difference between the bootstrap3 and bootstrap4:





PHP Versions


It supports >5.6 version of PHP.




Has the minimum version required of PHP is 7.2 or higher






It has 2 directories:


1. application

2. system



It has 5 directories:


1. app

2. system

3. public

4. writeable

5. tests







It does not use namespaces.


It is written in PHP7 architecture, so it supports namespaces.







It uses php5 so it has less performance as compared to php7.


It has better performance because of PHP7 architecture.



Native supports for .env files



It does not have any .env files.


It uses .env files for setting project modes such as production, development, test.







To run the project in CodeIgniter3 there are a number of settings to be performed.




In this CodeIgniter4, to run the project there are minimal settings as compared to CodeIgniter3.





To autoload files we have to manually configure them.



It has a more efficient process to autoload files because of namespaces.


Migration between versions



Migrating from Codeigniter2 to Codeigniter3 was very easy, we have to only overwrite the files.






CodeIgniter4 is not backward compatible. To migrate from CodeIgniter3 to CodeIgniter4 requires more effort.