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CodeIgniter 3 vs 4 – Major Differences You Need to Know

CodeIgniter 3 vs 4

CodeIgniter web framework is one of the powerful open-source PHP frameworks that is used for developing dynamic websites with PHP. Like any other framework, CodeIgniter also gets updated from time to time to provide its users with more features and high performance. As a leading CodeIgniter development company, we have been using the framework for years to develop robust, feature-rich, and dynamic websites. We also stay abreast with the latest versions and features that CI offers to build future-proof websites for our clients. In this article, we are going to discuss CodeIgniter 3 vs 4 – Major differences you need to know for CodeIgniter web development.

Before we jump into the topic directly, let’s first know a bit about what happened between the launch of CodeIgniter 3 and 4. It took almost 5 years, or 1767 days to be more precise to release the first stable version of CodeIgniter 4 after the release of CodeIgniter 3.

During these times, 8 versions of PHP were released, many other PHP frameworks emerged and the leading frameworks were being updated.

Meanwhile, the CI framework was lagging behind. It was gradually becoming one of the most outdated PHP frameworks. However, all was not lost. EllisLab who was mainly responsible for CodeIgniter development passed the baton to BCIT and with the efforts of Jim Perry and an extremely dedicated developers’ community, CodeIgniter has revived and the release of 4th version won its first alpha on 28 September 2018.

CodeIgniter 4 was released on 24th February 2020 which is Jim Perry’s birthday, in honor of the person who devoted a significant amount of time to making CodeIgniter strong enough to compete with other existing frameworks.

CodeIgniter 3 vs 4 Comparison

1. PHP Version Support

For using CodeIgniter 4, the minimum PHP version required is 7.2. CodeIgniter 3 requires using version 5.6, which has already been discontinued.

If you’re looking for CodeIgniter support services to upgrade to CodeIgniter 4, you can contact us right away.

2. Use of Namespaces

CodeIgniter 4 uses namespaces as it is written entirely in PHP 7 whereas CodeIgniter 3 does not make use of namespaces.

3. Organization of Directory

CodeIgniter 3 and 4 differ based on the file structure. CodeIgniter 4 comes with its structure organized in five directories /app,/system,/public,/writable,/tests. CodeIgniter 3 has its structure organized in two directories /application, and/system`.

4. Autoloading

When comparing CodeIgniter 3 vs 4 based on the autoload process, CodeIgniter 4 is much more efficient, mainly because of the use of namespaces. In the case of CodeIgniter 3, manual configuration of most of the files to be loaded is necessary.

5. Use of Entities

CodeIgniter 4 offers native support for using Entities that help in organizing the database part of an application to represent the existing columns in the tables. CodeIgniter 3 does not come with this feature, so users who needed to use it had to use third-party libraries and make adjustments to the file upload for supporting it.

If you need help with CodeIgniter web development, you can hire CodeIgniter developers from us to do the job for you.

6. Performance

Comparing CodeIgniter 3 vs 4 based on performance, CodeIgniter 4 has a better performance than CodeIgniter 3 when considering using PHP 7 in writing and as a minimum configuration on the server.

7. Settings

CodeIgniter 4 involves minimal initial settings for your application to start running. On the other hand, CodeIgniter 3 involves a good number of configurations that need to be performed.

8. Monolithic Libraries

CodeIgniter does not use monolithic libraries in the PEAR style, unlike CodeIgniter 3.

9. Native support for .env files

CodeIgniter 4 provides native support for .env files which helps in optimizing settings of the various environments where it may be running, be it production, development, or tests. CodeIgniter 3 does not provide this native support.

10. Application Migration from 3 to 4

As CodeIgniter is not backward compatible, the process of updating applications from CodeIgniter 3 to 4 requires more work, however, it is not at all complicated.

While migrating from CodeIgniter 2.x to 3.x and between the different versions 3.x was just about overwriting the files in the /system directory and updating the name of certain files, the migration from 3 to 4 requires a new structure for the application and rewriting of all the classes used in it to match the new standard.

You can hire CodeIgniter developers from us if you need to upgrade from current CodeIgniter version to its latest version.


So, these are some of the major differences between CodeIgniter 3 vs 4. As a professional CodeIgniter development company, we offer comprehensive range of CodeIgniter web development and other related services.

You may contact us for any kind of CodeIgniter development services. Whether it is CodeIgniter website development, CodeIgniter module development, or CodeIgniter support and maintenance, our developers have a knack for delivering the best-in-class CodeIgniter development services at an affordable price range.

Q.1. Can you help me migrate to CodeIgniter 4 from any other PHP framework?

Yes, of course. You can hire CodeIgniter developers from us who can help you migrate everything to CodeIgniter from any PHP framework you’re using.

Q.2. Why choose CodeIgniter over other frameworks?

CodeIgniter is recommended over other PHP frameworks because of the following reasons:

  • Open-source framework
  • Faster development
  • Effective file management
  • Great security functions
  • Simple configurations
  • Less Coding
  • Easy error handling
  • Template solutions
  • Stage by stage testing, and more.
Q.3. Is CodeIgniter easy to learn?

Yes. CodeIgniter is beginner-friendly as it comes with a simple configuration.

Need to Upgrade from CodeIgniter 3 to 4?

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