# Source: https://nextjs.org/docs/app/api-reference/config/next-config-js/turbopackFileSystemCache.md

# Turbopack FileSystem Caching
@doc-version: 16.0.4


## Usage

Turbopack FileSystem Cache enables Turbopack to reduce work across `next dev` or `next build` commands. When enabled, Turbopack will save and restore data to the `.next` folder between builds, which can greatly speed up subsequent builds and dev sessions.

> **Good to know:** The FileSystem Cache feature is Beta and is still under development. Users adopting should expect some stability issues. We recommend first adopting it for development.

```ts filename="next.config.ts" switcher
import type { NextConfig } from 'next'

const nextConfig: NextConfig = {
  experimental: {
    // Enable filesystem caching for `next dev`
    turbopackFileSystemCacheForDev: true,
    // Enable filesystem caching for `next build`
    turbopackFileSystemCacheForBuild: true,
  },
}

export default nextConfig
```

```js filename="next.config.js" switcher
/** @type {import('next').NextConfig} */
const nextConfig = {
  experimental: {
    // Enable filesystem caching for `next dev`
    turbopackFileSystemCacheForDev: true,
    // Enable filesystem caching for `next build`
    turbopackFileSystemCacheForBuild: true,
  },
}

module.exports = nextConfig
```

## Version Changes

| Version   | Changes                                                        |
| --------- | -------------------------------------------------------------- |
| `v16.0.0` | Beta release with separate flags for build and dev             |
| `v15.5.0` | Persistent caching released as experimental on canary releases |