Environment Variables

Since the release of Next.js 9.4 we now have a more intuitive and ergonomic experience for adding environment variables. Give it a try!


To add environment variables to the JavaScript bundle, open next.config.js and add the env config:

module.exports = { env: { customKey: 'my-value', }, }

Now you can access process.env.customKey in your code. For example:

function Page() { return <h1>The value of customKey is: {process.env.customKey}</h1> } export default Page

Next.js will replace process.env.customKey with 'my-value' at build time. Trying to destructure process.env variables won't work due to the nature of webpack DefinePlugin.

For example, the following line:

return <h1>The value of customKey is: {process.env.customKey}</h1>

Will end up being:

return <h1>The value of customKey is: {'my-value'}</h1>