# Next

## Module

To simply configure PurgeCSS with next.js, you can use [next-purgecss](https://github.com/lucleray/next-purgecss).

## Installation

### 1. Install the packages

`next-purgecss` requires one of the following **css next plugins** :

* [next-css](https://github.com/zeit/next-plugins/tree/master/packages/next-css)
* [next-less](https://github.com/zeit/next-plugins/tree/master/packages/next-less)
* [next-sass](https://github.com/zeit/next-plugins/tree/master/packages/next-sass)

Just pick the one that fits your needs. In the following steps, I will use `next-css` but it works the same for the other **css next plugins**.

For example, install `next-css` and `next-purgecss` :

```
yarn add @zeit/next-css next-purgecss --dev
```

or with npm :

```
npm install @zeit/next-css next-purgecss --save-dev
```

### 2. Edit `next.config.js`.

```javascript
// next.config.js
const withCss = require('@zeit/next-css')
const withPurgeCss = require('next-purgecss')

module.exports = withCss(withPurgeCss())
```

## Options

By default, this plugin will scan `components` and `pages` directories for classnames.

Under the hood, `next-purgecss` uses the PurgeCSS Webpack Plugin. You can pass custom options to the plugin by defining `purgeCss` object in your `next.config.js` :

```javascript
// next.config.js
module.exports = withCss(
  withPurgeCss({
    purgeCss: {
      whitelist: () => ['my-custom-class']
    }
  })
)
```

See the page dedicated to the [PurgeCSS Webpack Plugin](/with-webpack.md) for more information.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://v1.purgecss.com/guides/next.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.