cssnano-webpack-plugin

This plugin uses cssnano to optimize and minify your CSS.

Fully integrated in Webpack ecosystem: based on compiler hooks, respecting default Webpack output sources and compatible with other plugins like SourceMapDevToolPlugin or webpack-subresource-integrity.

Just like optimize-css-assets-webpack-plugin but more accurate with source maps and assets using query string.

Works with Webpack 4+.

Getting Started

First, install cssnano-webpack-plugin:

$ npm install cssnano-webpack-plugin --save-dev

Then add the plugin to your webpack configuration. For example:

webpack.config.js

const CssnanoPlugin = require('cssnano-webpack-plugin');

module.exports = {
  module: {
    loaders: [
      {
        test: /.s?css$/,
        use: [
          MiniCssExtractPlugin.loader,
          'css-loader',
          'sass-loader'
        ]
      }
    ]
  },
  optimization: {
    minimizer: [
      new CssnanoPlugin()
    ]
  }
};

This will enable CSS optimization only in production mode. If you want to run it also in development, put the plugin configuration in the plugins option array.

Options

`test`

Type: String|RegExp|Array<String|RegExp> - default: /\.css(\?.*)?$/i

Test to match files against.

module.exports = {
  optimization: {
    minimizer: [
      new CssnanoPlugin({
        test: /\.foo\.css$/i
      })
    ]
  }
};

include and exclude options are also supported (see module rules).

`sourceMap`

Type: Boolean|Object - default: false

Enable (and configure) source map support. Use PostCss SourceMap options. Default configuration when enabled: { inline: false }.

module.exports = {
  optimization: {
    minimizer: [
      new CssnanoPlugin({
        sourceMap: true
      })
    ]
  }
};

`cssnanoOptions`

Type: Object - default: { preset: 'default' }

Cssnano optimisations options.

module.exports = {
  optimization: {
    minimizer: [
      new CssnanoPlugin({
        cssnanoOptions: {
          preset: ['default', {
            discardComments: { removeAll: true }
          }]
        }
      })
    ]
  }
};

Examples

Use sourcemaps

Don't forget to enable sourceMap options for all loaders.

const CssnanoPlugin = require('cssnano-webpack-plugin');

module.exports = {
  module: {
    loaders: [
      {
        test: /.s?css$/,
        use: [
          MiniCssExtractPlugin.loader,
          { loader: 'css-loader', options: { sourceMap: true } },
          { loader: 'sass-loader', options: { sourceMap: true } }
        ]
      }
    ]
  },
  optimization: {
    minimizer: [
      new CssnanoPlugin({
        sourceMap: true
      })
    ]
  }
};

Remove all comments

Remove all comments (including comments starting with /*!).

module.exports = {
  optimization: {
    minimizer: [
      new CssnanoPlugin({
        cssnanoOptions: {
          preset: ['default', {
            discardComments: { removeAll: true }
          }]
        }
      })
    ]
  }
};

License

MIT