> ## Documentation Index
> Fetch the complete documentation index at: https://kb.hosting.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Migrating an existing Node.js application to Node.js Selector

> Learn how to migrate your Node.js application to cPanel's Node.js Selector. Just follow our easy step-by-step instructions!

This article describes how to migrate an existing Node.js application to the Node.js Selector in cPanel.

## Migrating an application

In most cases, Node.js applications can be migrated to Node.js Selector with only minor modifications. To do this, follow these steps:

1. Log in to cPanel.
   > 📘 Note
   >
   > If you do not know how to log in to your cPanel account, please see [this article](/docs/accessing-cpanel).

2. Create a new application using Node.js Selector.
   > 📘 Note
   >
   > For information about how to create a new Node.js application using the Node.js Selector in cPanel, please see [this article](/docs/create-application-with-nodejs-selector).

3. Copy the existing Node.js application files to the application root directory.

4. Modify the script files for the Node.js Selector environment as follows:

   * **Port number**: If your existing application uses a hard-coded port number, you should change it to obtain a port number dynamically. The exact method to do this varies based on the application. For example, consider the following Express Node.js application code, which uses port 3000:

     ```javascript theme={null}
     const express = require('express')
     const app = express()
     const port = 3000

     app.get('/myapp', (req, res) => res.send('Hello World!'))

     app.listen(port, () => console.log('Example app listening at http://localhost:${port}'))
     ```

     You can modify this code to obtain a port number dynamically as follows:

     ```javascript theme={null}
     const express = require('express')
     const app = express()

     app.get('/myapp', (req, res) => res.send('Hello World!'))

     const server = app.listen(0, () => {
         console.log('Example app listening at http://localhost:', server.address().port);
     });
     ```

     The parameter 0 in the **app.listen()** statement instructs Node.js to obtain a port number dynamically.

   * **Import directives**: Some Node.js versions do not support **import** directives. Therefore, you should modify any **import** statements to use **require** instead. For example, consider the following statements:

     ```
     import express from "express";
     import path from "path";
     import dotenv from "dotenv";
     ```

     These statements can be modified to work correctly as follows:

     ```
     const express = require('express');
     const path = require('path');
     const dotenv = require('dotenv');
     ```

   * **Routes:** You may have to modify the routes in your code to include the application URL. For more information, please see [this article](/docs/node-js-application-error-message-cannot-get-url).

## Related articles

* [Creating a Node.js application with cPanel using the Node.js Selector](/docs/create-application-with-nodejs-selector)

* [Node.js application error message: "Cannot GET" URL](/docs/node-js-application-error-message-cannot-get-url)