Next.js next.config.js Options

The next.config.js file is used to configure various aspects of a Next.js application. It allows developers to customize the behavior of the Next.js server, modify the webpack configuration, add environment variables, and more. This page outlines some of the available options that can be used in the next.config.js file.

Syntax

The next.config.js file exports a configuration object. The available options are properties on this object. For example:

module.exports = {
  /* options go here */
}

Example

module.exports = {
  webpack(config, options) {
    config.module.rules.push({
      test: /\.svg$/,
      use: ["@svgr/webpack"]
    });

    return config;
  },
  env: {
    MY_SECRET: process.env.MY_SECRET
  }
}

In this example, we are adding a webpack rule to handle SVG files using the @svgr/webpack package, and we are exposing an environment variable called MY_SECRET to the Next.js application.

Output

The output of the next.config.js file is the modified configuration used by the Next.js application. In the example above, when the Next.js server is started, it will use the modified webpack configuration and make the MY_SECRET environment variable available to the application.

Explanation

The next.config.js file is used to modify the default configuration of a Next.js application. It provides developers with the ability to customize various aspects of the application, such as the webpack configuration or environment variables.

Use

Developers can use the next.config.js file to modify various aspects of their Next.js application. Some use cases for the next.config.js file include:

• Customizing the webpack configuration
• Adding environment variables
• Adding plugins
• Defining custom routes

Important Points

• The next.config.js file is only used during the development and production builds of the Next.js application. It is not used at runtime.

• Changes made in the next.config.js file will override the default Next.js configuration.

• The next.config.js file must export a configuration object.

Summary

The next.config.js file is a powerful tool for configuring a Next.js application. It can be used to modify the default webpack configuration, add environment variables or plugins, define custom routes, and more. Changes to the next.config.js file will override the default Next.js configuration, and it must export a configuration object.