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# webpack
## Removing unused languages from dynamic import
If a locale is imported dynamically, then all locales from date-fns are loaded by webpack into a bundle (~160kb) or split across the chunks. This prolongs the build process and increases the amount of space taken. However, it is possible to use webpack to trim down languages using [ContextReplacementPlugin].
Let's assume that we have a single point in which supported locales are present:
`config.js`:
```js
// `see date-fns/src/locale` for available locales
export const supportedLocales = ['en-US', 'de', 'pl', 'it']
```
We could also have a function that formats the date:
```js
const getLocale = (locale) => import(`date-fns/locale/${locale}/index.js`) // or require() if using CommonJS
const formatDate = (date, formatStyle, locale) => {
return format(date, formatStyle, {
locale: getLocale(locale),
})
}
```
In order to exclude unused languages we can use webpacks [ContextReplacementPlugin].
`webpack.config.js`:
```js
import webpack from 'webpack'
import { supportedLocales } from './config.js'
export default const config = {
plugins: [
new webpack.ContextReplacementPlugin(
/date\-fns[\/\\]/,
new RegExp(`[/\\\\\](${supportedLocales.join('|')})[/\\\\\]index\.js$`)
)
]
}
```
This results in a language bundle of ~23kb .
[contextreplacementplugin]: https://webpack.js.org/plugins/context-replacement-plugin/
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