How to Fix SyntaxError: Cannot Use Import Statement Outside a Module

In modern JavaScript development, developers often encounter the error “SyntaxError: Cannot use import statement outside a module” when attempting to use the ES6 import statement for module imports. This error occurs because the JavaScript environment does not recognize the ES6 module syntax by default. This article will guide you through understanding the cause of this error and provide solutions to resolve it in various development environments.

Understanding ES6 Modules

ECMAScript 6 (ES6), also known as ECMAScript 2015, introduced the concept of modules to JavaScript. Modules allow you to split your code into separate, reusable components, which can be imported and exported using the import and export statements. However, to use ES6 modules, your JavaScript environment must be configured to understand and process the module syntax.

Resolving the SyntaxError in Different Environments

1. Node.js

Node.js added native support for ES6 modules in version 13.2.0. To use the import statement in Node.js, you need to set the “type” field in your package.json file:

{
  "name": "your-project",
  "version": "1.0.0",
  "type": "module"
}

By setting the “type” field to “module,” you inform Node.js that you want to use ES6 module syntax in your project. If you’re using an older version of Node.js that doesn’t support ES6 modules, consider upgrading to a newer version or using the CommonJS require() syntax instead.

2. Babel

If you’re using Babel to transpile your JavaScript code, ensure that you have the correct configuration in your .babelrc or babel.config.js file. You’ll need the @babel/plugin-syntax-dynamic-import and @babel/plugin-transform-modules-commonjs plugins to handle the import statements:

Install the required plugins:

enpm install --save-dev @babel/plugin-syntax-dynamic-import @babel/plugin-transform-modules-commonjs

Add the plugins to your Babel configuration:

{
  "plugins": [
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-transform-modules-commonjs"
  ]
}

3. Webpack

If you’re using Webpack to bundle your JavaScript code, ensure that you’re using the correct loader, such as babel-loader, to transpile your ES6 modules to a format that browsers can understand:

Install the required loader and Babel dependencies:

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

Configure the loader in your webpack.config.js file:

module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env']
          }
        }
      }
    ]
  }
};

4. HTML Files

To use the import statement directly in your HTML files, ensure that you include the type="module" attribute in your script tags:

e<script type="module" src="your-script.js"></script>

By setting the type attribute to “module,” you inform the browser that the script should be treated as an ES6 module, allowing the use of the import statement.

Conclusion

The “SyntaxError: Cannot use import statement outside a module” error can be resolved by configuring your JavaScript environment correctly.