---
navigation.icon: IconFile
title: ".env"
description: "A .env file specifies your build/dev-time environment variables."
head.title: ".env"
---

# .env File

Nuxt CLI has built-in [dotenv](https://github.com/motdotla/dotenv) support in development mode and when running `nuxi build` and `nuxi generate`.

In addition to any process environment variables, if you have a `.env` file in your project root directory, it will be automatically loaded **at build, dev, and generate time**, and any environment variables set there will be accessible within your `nuxt.config` file and modules.

::alert
If you want to use a different file - for example, to use `.env.local` or `.env.production` - you can do so by passing the `--dotenv` flag when using `nuxi`. For example:

```bash
npx nuxi dev --dotenv .env.local
```

Just as above, this will only apply in development mode and when running `nuxi build` and `nuxi generate`.
::

When updating `.env` in development mode, the Nuxt instance is automatically restarted to apply new values to the `process.env`.

::alert{type=warning}
Note that removing a variable from `.env` or removing the `.env` file entirely will not unset values that have already been set.
::

However, **after your server is built**, you are responsible for setting environment variables when you run the server. Your `.env` file will not be read at this point. How you do this is different for every environment. On a Linux server, you could pass the environment variables as arguments using the terminal `DATABASE_HOST=mydatabaseconnectionstring node .output/server/index.mjs`. Or you could source your env file using `source .env && node .output/server/index.mjs`.

Note that for a purely static site, it is not possible to set runtime configuration config after your project is prerendered.

:ReadMore{link="/docs/guide/going-further/runtime-config"}

If you want to use environment variables set at build time but do not care about updating these down the line (or only need to update them reactively _within_ your app) then `appConfig` may be a better choice. You can define `appConfig` both within your `nuxt.config` (using environment variables) and also within an `~/app.config.ts` file in your project.

:ReadMore{link="/docs/guide/directory-structure/app-config"}