CodeIgniter 4 How To Read Parse JSON File Tutorial

Reading Time: 4 minutes

JSON (JavaScript Object Notation) files stand as a prevalent format for storing structured data, often used for configuration settings, API responses, or data interchange. In CodeIgniter 4, parsing JSON files enables developers to effortlessly handle and extract structured data within their applications.

In this tutorial, we’ll see the comprehensive process of reading and parsing JSON files using CodeIgniter 4. This functionality empowers developers to efficiently handle structured data stored in JSON format within their applications.

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Let’s get started.

CodeIgniter 4 Installation

To create a CodeIgniter 4 setup run this given command into your shell or terminal. Please make sure composer should be installed.

composer create-project codeigniter4/appstarter codeigniter-4

Assuming you have successfully installed application into your local system.

Environment (.env) Setup

When we install CodeIgniter 4, we will have env file at root. To use the environment variables means using variables at global scope we need to do env to .env

Either we can do via renaming file as simple as that. Also we can do by terminal command.

Open project in terminal

cp env .env

Above command will create a copy of env file to .env file. Now we are ready to use environment variables.

Enable Development Mode

CodeIgniter starts up in production mode by default. You need to make it in development mode to see any error if you are working with application.

Open .env file from root.

# CI_ENVIRONMENT = production

 // Do it to 
CI_ENVIRONMENT = development

Now application is in development mode.

JSON Data Preparation

Let’s consider a .json file in application. We have a students.json inside /writable folder.

		"name": "Sanjay Kumar",
		"email": ""
		"name": "Ashish Kumar",
		"email": ""
		"name": "Dhananjay Negi",
		"email": ""
		"name": "Vijay Rohila",
		"email": ""

You can place this .json file either in /writable folder or /public folder.

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Create Controller

Assuming .json file is placed within /writable folder.

Open project into terminal and run this spark command.

php spark make:controller Site --suffix

It will create a file SiteController.php inside /app/Controllers folder.

Open file and write this complete code into it.


namespace App\Controllers;

use App\Controllers\BaseController;

class SiteController extends BaseController
    public function index()
        $students = json_decode(file_get_contents(WRITEPATH."students.json"), true);

        echo "<pre>";


$students = json_decode(file_get_contents(WRITEPATH."students.json"), true);

Here, we are parsing students.json file. WRITEPATH is a CodeIgniter 4 constant which returns the path upto /writable folder.

If you have taken /public folder then you should use FCPATH in place of it. json_decode returns the data in object format. But putting true as second value it returns the data into array format.

Once you get data from .json into array format, you can insert into your database as well.

Create Route

Open Routes.php from /app/Config folder. Add this route into it.


$routes->get('/data', 'SiteController::index');


Application Testing

Open project terminal and start development server via command:

php spark serve

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URL: http://localhost:8080/data

That’s it.

We hope this article helped you to learn about How To Read Parse JSON File in CodeIgniter 4 Tutorial in a very detailed way.

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Sanjay KumarHello friends, I am Sanjay Kumar a Web Developer by profession. Additionally I'm also a Blogger, Youtuber by Passion. I founded Online Web Tutor and Skillshike platforms. By using these platforms I am sharing the valuable knowledge of Programming, Tips and Tricks, Programming Standards and more what I have with you all. Read more