Understanding the Default Port for a Create-React-App Project

When you set up a new project using create-react-app, the default port it runs on is 3000.

This is designed this way because the port is an important aspect of network communication. It allows different processes running on the same machine to communicate with each other. When you start your project with npm start or yarn start, the Create React App (CRA) development server will automatically start serving up your new app on this port.

Practical Example

So, let's consider a practical scenario. When we start our React app using the Create React App setup, we might run the following command in our terminal,

npm start

After processing, we will see a message indicating where our app is being served. Something like,

Starting development server...
Compiled successfully!

You can now view my-app in the browser.

Local: http://localhost:3000

This indicates that our app can be accessed at http://localhost:3000. This URL represents your own machine (localhost), and the 3000 after the colon is the port number.

Modifications and Best Practices

It's important to note that while port 3000 is the default, it can be modified according to your needs. To do this, you can set the environment variable PORT in the .env file for your project, like PORT=8000, and the project will start on the specified port instead.

Keep in mind, however, that if you're planning on deploying your application, most hosting platforms will assign a port for you, so it's a good practice to ensure your app can adapt to different ports with relative ease.

In conclusion, the default port on which a Create React App project runs is 3000. But always remember, this is a customizable aspect of your development process and you should be prepared to adapt it to changing requirements.