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---
title: How to configure Babel in Next.js
nav_title: Babel
description: Extend the babel preset added by Next.js with your own configs.
---
<details>
<summary>Examples</summary>
- [Customizing babel configuration](https://github.com/vercel/next.js/tree/canary/examples/with-custom-babel-config)
</details>
Next.js includes the `next/babel` preset to your app, which includes everything needed to compile React applications and server-side code. But if you want to extend the default Babel configs, it's also possible.
## Adding Presets and Plugins
To start, you only need to define a `.babelrc` file (or `babel.config.js`) in the root directory of your project. If such a file is found, it will be considered as the _source of truth_, and therefore it needs to define what Next.js needs as well, which is the `next/babel` preset.
Here's an example `.babelrc` file:
```json filename=".babelrc"
{
"presets": ["next/babel"],
"plugins": []
}
```
You can [take a look at this file](https://github.com/vercel/next.js/blob/canary/packages/next/src/build/babel/preset.ts) to learn about the presets included by `next/babel`.
To add presets/plugins **without configuring them**, you can do it this way:
```json filename=".babelrc"
{
"presets": ["next/babel"],
"plugins": ["@babel/plugin-proposal-do-expressions"]
}
```
## Customizing Presets and Plugins
To add presets/plugins **with custom configuration**, do it on the `next/babel` preset like so:
```json filename=".babelrc"
{
"presets": [
[
"next/babel",
{
"preset-env": {},
"transform-runtime": {},
"styled-jsx": {},
"class-properties": {}
}
]
],
"plugins": []
}
```
To learn more about the available options for each config, visit babel's [documentation](https://babeljs.io/docs/) site.
> **Good to know**:
>
> - Next.js uses the [**current** Node.js version](https://github.com/nodejs/release#release-schedule) for server-side compilations.
> - The `modules` option on `"preset-env"` should be kept to `false`, otherwise webpack code splitting is turned off.
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