How to Specify a Default Port for Your React App

In a React application, the default behavior is for the app to automatically create a separate port for you. However, there may be situations where you want to specify a specific port for your React app. Fortunately, there are two simple ways to achieve this. In this blog post, we will explore these two methods and guide you through the process of setting a default port for your React application.

Method 1: Using an .env File

The first method involves creating a .env file in your project directory, right beside the package.json file. This file allows you to set environment variables for your React app. To specify a port using this method, follow these steps:

1. Create a file named .env in the root of your project directory.

2. Open the .env file and add the following line: PORT=<port number>, replacing <port number> with the desired port number.

For example, if you want your app to run on port 3456, the line in your .env file should be: PORT=3456.

Method 2: Modifying the package.json File

The second method involves modifying the package.json file of your React app. This method allows you to change the port configuration directly in the scripts section. Follow these steps to specify a port using this method:

1. Locate the scripts section in your package.json file. It typically looks like this:

2.   "scripts": {
       "start": "react-scripts start",
       "build": "react-scripts build",
       "test": "react-scripts test",
       "eject": "react-scripts eject"
     }
   

3. Modify the value of the "start" key to include the port specification. The exact modification depends on your operating system:

• For Windows:

•     "start": "set PORT=<port number> && react-scripts start"
  

  Replace <port number> with the desired port number, for example: "start": "set PORT=3456 && react-scripts start".

  • For macOS or Linux:

  •     "start": "PORT=<port number> react-scripts start"
    

    Again, replace <port number> with the desired port number, for example: "start": "PORT=3456 react-scripts start".

    Conclusion: By following either of these two methods, you can easily specify a default port for your React app. Whether you choose to use an .env file or modify the package.json file directly, you have the flexibility to run your React application on a specific port of your choice.

    This can be particularly useful when integrating with other services or when you have port-related requirements. Experiment with these methods and enjoy a customized port configuration for your React app.

  • Happy coding 💻💻