Nextjs Turbopack

# Next.js and Turbopack

Next.js 16+ uses Turbopack by default for local development: an incremental bundler written in Rust that significantly speeds up dev startup and hot updates.

## When to Use

- **Turbopack (default dev)**: Use for day-to-day development. Faster cold start and HMR, especially in large apps.
- **Webpack (legacy dev)**: Use only if you hit a Turbopack bug or rely on a webpack-only plugin in dev. Disable with `--webpack` (or `--no-turbopack` depending on your Next.js version; check the docs for your release).
- **Production**: Production build behavior (`next build`) may use Turbopack or webpack depending on Next.js version; check the official Next.js docs for your version.

Use when: developing or debugging Next.js 16+ apps, diagnosing slow dev startup or HMR, or optimizing production bundles.

## How It Works

- **Turbopack**: Incremental bundler for Next.js dev. Uses file-system caching so restarts are much faster (e.g. 5–14x on large projects).
- **Default in dev**: From Next.js 16, `next dev` runs with Turbopack unless disabled.
- **File-system caching**: Restarts reuse previous work; cache is typically under `.next`; no extra config needed for basic use.
- **Bundle Analyzer (Next.js 16.1+)**: Experimental Bundle Analyzer to inspect output and find heavy dependencies; enable via config or experimental flag (see Next.js docs for your version).

## Examples

### Commands

```bash
next dev
next build
next start
```

### Usage