How to Fix Unexpected Token ‘import’ Error in Node.js

Introduction

The Unexpected Token 'import' error is common in Node.js when working with ES6 modules. This issue typically arises due to a mismatch between the module system being used (CommonJS vs ES6). In this blog, we will explain the causes of the error and provide simple solutions.

Why Does the “Unexpected Token ‘import'” Error Occur?

Node.js traditionally uses the CommonJS module system, which relies on the require syntax. However, ES6 introduced import and export syntax, which is not supported by default in older Node.js versions or without proper configuration.

The error occurs when Node.js encounters an import statement it cannot process.

Error Example

SyntaxError: Unexpected token 'import'
        

This typically happens when you try to run the following code:

// File: index.js
import express from 'express';
const app = express();
        

Solutions for “Unexpected Token ‘import'”

Here are some effective ways to resolve this error:

1. Update Your Node.js Version

Ensure you are using Node.js version 12 or higher, as these versions support ES6 modules with some configurations. Run the following command to check your Node.js version:

node -v

If you have an older version, update Node.js by downloading the latest version from the official website.

2. Use the type Field in package.json

To enable ES6 modules in your project, set the type field in your package.json file to module:

{
  "type": "module"
}
        

This allows Node.js to recognize import and export statements.

3. Use .mjs File Extension

Rename your JavaScript files to have a .mjs extension instead of .js. Node.js treats .mjs files as ES6 modules by default.

4. Stick to require Syntax

If you don’t need ES6 modules, revert to the CommonJS syntax by replacing import with require:

// Replace this:
import express from 'express';

// With this:
const express = require('express');
        

5. Use a Transpiler (e.g., Babel)

If you want to use ES6 modules in older Node.js versions, configure Babel to transpile your ES6 code to CommonJS. Install Babel and configure it as follows:

npm install --save-dev @babel/core @babel/cli @babel/preset-env
        

Create a .babelrc file with this content:

{
  "presets": ["@babel/preset-env"]
}
        

Then transpile your code with:

npx babel src --out-dir dist

Conclusion

The “Unexpected Token ‘import'” error occurs when Node.js encounters ES6 syntax it doesn’t recognize. By updating your Node.js version, using the type field, or sticking to CommonJS syntax, you can easily resolve this issue. For larger projects, a transpiler like Babel may be necessary.

With these solutions, you can confidently use ES6 modules in your Node.js applications.