--- title: next CLI description: Learn how to run and build your application with the Next.js CLI. url: "https://nextjs.org/docs/pages/api-reference/cli/next" version: 16.2.2 lastUpdated: 2026-04-02 router: Pages Router prerequisites: - "API Reference: /docs/pages/api-reference" - "CLI: /docs/pages/api-reference/cli" --- The Next.js CLI allows you to develop, build, start your application, and more. Basic usage: ```bash package="pnpm" pnpm next [command] [options] ``` ```bash package="npm" npx next [command] [options] ``` ```bash package="yarn" yarn next [command] [options] ``` ```bash package="bun" bunx next [command] [options] ``` > **Good to know**: With `npm run`, use `--` before CLI flags so npm forwards them to `next`. This is not required for `pnpm`, `yarn`, or `bun`. ## Reference The following options are available: | Options | Description | | ------------------- | ---------------------------------- | | `-h` or `--help` | Shows all available options | | `-v` or `--version` | Outputs the Next.js version number | ### Commands The following commands are available: | Command | Description | | ------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------- | | [`dev`](#next-dev-options) | Starts Next.js in development mode with Hot Module Reloading, error reporting, and more. | | [`build`](#next-build-options) | Creates an optimized production build of your application. Displaying information about each route. | | [`start`](#next-start-options) | Starts Next.js in production mode. The application should be compiled with `next build` first. | | [`info`](#next-info-options) | Prints relevant details about the current system which can be used to report Next.js bugs. | | [`telemetry`](#next-telemetry-options) | Allows you to enable or disable Next.js' completely anonymous telemetry collection. | | [`typegen`](#next-typegen-options) | Generates TypeScript definitions for routes, pages, layouts, and route handlers without running a full build. | | [`upgrade`](#next-upgrade-options) | Upgrades your Next.js application to the latest version. | | [`experimental-analyze`](#next-experimental-analyze-options) | Analyzes bundle output using Turbopack. Does not produce build artifacts. | > **Good to know**: Running `next` without a command is an alias for `next dev`. ### `next dev` options `next dev` starts the application in development mode with Hot Module Reloading (HMR), error reporting, and more. > **Good to know**: Development builds output to `.next/dev` instead of `.next`. This allows you to run `next dev` and `next build` concurrently without conflicts. The following options are available when running `next dev`: | Option | Description | | ---------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- | | `-h, --help` | Show all available options. | | `[directory]` | A directory in which to build the application. If not provided, current directory is used. | | `--turbopack` | Force enable [Turbopack](/docs/app/api-reference/turbopack) (enabled by default). Also available as `--turbo`. | | `--webpack` | Use Webpack instead of the default [Turbopack](/docs/app/api-reference/turbopack) bundler for development. | | `-p` or `--port ` | Specify a port number on which to start the application. Default: 3000, env: PORT | | `-H`or `--hostname ` | Specify a hostname on which to start the application. Useful for making the application available for other devices on the network. Default: 0.0.0.0 | | `--experimental-https` | Starts the server with HTTPS and generates a self-signed certificate. | | `--experimental-https-key ` | Path to a HTTPS key file. | | `--experimental-https-cert ` | Path to a HTTPS certificate file. | | `--experimental-https-ca ` | Path to a HTTPS certificate authority file. | | `--experimental-upload-trace ` | Reports a subset of the debugging trace to a remote HTTP URL. | | `--experimental-cpu-prof` | Enables CPU profiling using V8's inspector. Profiles are saved to `.next/cpu-profiles/` on exit. | ### `next build` options `next build` creates an optimized production build of your application. The output displays information about each route. For example: ```bash filename="Terminal" Route (app) ┌ ○ /_not-found └ ƒ /products/[id] ○ (Static) prerendered as static content ƒ (Dynamic) server-rendered on demand ``` The following options are available for the `next build` command: | Option | Description | | ---------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `-h, --help` | Show all available options. | | `[directory]` | A directory on which to build the application. If not provided, the current directory will be used. | | `--turbopack` | Force enable [Turbopack](/docs/app/api-reference/turbopack) (enabled by default). Also available as `--turbo`. | | `--webpack` | Build using Webpack. | | `-d` or `--debug` | Enables a more verbose build output. With this flag enabled additional build output like rewrites, redirects, and headers will be shown. | | | | `--profile` | Enables production [profiling for React](https://react.dev/reference/react/Profiler). | | `--no-lint` | Disables linting. *Note: linting will be removed from `next build` in Next 16. If you're using Next 15.5+ with a linter other than `eslint`, linting during build will not occur.* | | `--no-mangling` | Disables [mangling](https://en.wikipedia.org/wiki/Name_mangling). This may affect performance and should only be used for debugging purposes. | | `--experimental-app-only` | Builds only App Router routes. | | `--experimental-build-mode [mode]` | Uses an experimental build mode. (choices: "compile", "generate", default: "default") | | `--debug-prerender` | Debug prerender errors in development. | | `--debug-build-paths=` | Build only specific routes for debugging. | | `--experimental-cpu-prof` | Enables CPU profiling using V8's inspector. Profiles are saved to `.next/cpu-profiles/` on exit. | ### `next start` options `next start` starts the application in production mode. The application should be compiled with [`next build`](#next-build-options) first. The following options are available for the `next start` command: | Option | Description | | --------------------------------------- | --------------------------------------------------------------------------------------------------------------- | | `-h` or `--help` | Show all available options. | | `[directory]` | A directory on which to start the application. If no directory is provided, the current directory will be used. | | `-p` or `--port ` | Specify a port number on which to start the application. (default: 3000, env: PORT) | | `-H` or `--hostname ` | Specify a hostname on which to start the application (default: 0.0.0.0). | | `--keepAliveTimeout ` | Specify the maximum amount of milliseconds to wait before closing the inactive connections. | | `--experimental-cpu-prof` | Enables CPU profiling using V8's inspector. Profiles are saved to `.next/cpu-profiles/` on exit. | ### `next info` options `next info` prints relevant details about the current system which can be used to report Next.js bugs when opening a [GitHub issue](https://github.com/vercel/next.js/issues). This information includes Operating System platform/arch/version, Binaries (Node.js, npm, Yarn, pnpm), package versions (`next`, `react`, `react-dom`), and more. The output should look like this: ```bash filename="Terminal" Operating System: Platform: darwin Arch: arm64 Version: Darwin Kernel Version 23.6.0 Available memory (MB): 65536 Available CPU cores: 10 Binaries: Node: 20.12.0 npm: 10.5.0 Yarn: 1.22.19 pnpm: 9.6.0 Relevant Packages: next: 15.0.0-canary.115 // Latest available version is detected (15.0.0-canary.115). eslint-config-next: 14.2.5 react: 19.0.0-rc react-dom: 19.0.0 typescript: 5.5.4 Next.js Config: output: N/A ``` The following options are available for the `next info` command: | Option | Description | | ---------------- | ---------------------------------------------- | | `-h` or `--help` | Show all available options | | `--verbose` | Collects additional information for debugging. | ### `next telemetry` options Next.js collects **completely anonymous** telemetry data about general usage. Participation in this anonymous program is optional, and you can opt-out if you prefer not to share information. The following options are available for the `next telemetry` command: | Option | Description | | ------------ | --------------------------------------- | | `-h, --help` | Show all available options. | | `--enable` | Enables Next.js' telemetry collection. | | `--disable` | Disables Next.js' telemetry collection. | Learn more about [Telemetry](/telemetry). ### `next typegen` options `next typegen` generates TypeScript definitions for your application's routes without performing a full build. This is useful for IDE autocomplete and CI type-checking of route usage. Previously, route types were only generated during `next dev` or `next build`, which meant running `tsc --noEmit` directly wouldn't validate your route types. Now you can generate types independently and validate them externally: ```bash filename="Terminal" # Generate route types first, then validate with TypeScript next typegen && tsc --noEmit # Or in CI workflows for type checking without building next typegen && npm run type-check ``` The following options are available for the `next typegen` command: | Option | Description | | ------------- | -------------------------------------------------------------------------------------------- | | `-h, --help` | Show all available options. | | `[directory]` | A directory on which to generate types. If not provided, the current directory will be used. | Output files are written to `/types` (typically: `.next/dev/types` in development or `.next/types` in production): ```bash filename="Terminal" next typegen # or for a specific app next typegen ./apps/web ``` Additionally, `next typegen` generates a `next-env.d.ts` file. We recommend adding `next-env.d.ts` to your `.gitignore` file. The `next-env.d.ts` file is included into your `tsconfig.json` file, to make Next.js types available to your project. To ensure `next-env.d.ts` is present before type-checking run `next typegen`. The commands `next dev` and `next build` also generate the `next-env.d.ts` file, but it is often undesirable to run these just to type-check, for example in CI/CD environments. > **Good to know**: `next typegen` loads your Next.js config (`next.config.js`, `next.config.mjs`, or `next.config.ts`) using the production build phase. Ensure any required environment variables and dependencies are available so the config can load correctly. ### `next upgrade` options `next upgrade` upgrades your Next.js application to the latest version. The following options are available for the `next upgrade` command: | Option | Description | | ----------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | | `-h, --help` | Show all available options. | | `[directory]` | A directory with the Next.js application to upgrade. If not provided, the current directory will be used. | | `--revision ` | Specify a Next.js version or tag to upgrade to (e.g., `latest`, `canary`, `15.0.0`). Defaults to the release channel you have currently installed. | | `--verbose` | Show verbose output during the upgrade process. | ### `next experimental-analyze` options `next experimental-analyze` analyzes your application's bundle output using [Turbopack](/docs/app/api-reference/turbopack). This command helps you understand the size and composition of your bundles, including JavaScript, CSS, and other assets. This command doesn't produce an application build. ```bash package="pnpm" pnpm next experimental-analyze ``` ```bash package="npm" npx next experimental-analyze ``` ```bash package="yarn" yarn next experimental-analyze ``` ```bash package="bun" bunx next experimental-analyze ``` By default, the command starts a local server after analysis completes, allowing you to explore your bundle composition in the browser. The analyzer lets you: * Filter bundles by route and switch between client and server views * View the full import chain showing why a module is included * Trace imports across server-to-client component boundaries and dynamic imports See [Package Bundling](/docs/app/guides/package-bundling#optimizing-large-bundles) for optimization strategies. To write the analysis output to disk without starting the server, use the `--output` flag. The output is written to `.next/diagnostics/analyze` and contains static files that can be copied elsewhere or shared with others: ```bash filename="Terminal" # Write output to .next/diagnostics/analyze npx next experimental-analyze --output # Copy the output for comparison with a future analysis cp -r .next/diagnostics/analyze ./analyze-before-refactor ``` The following options are available for the `next experimental-analyze` command: | Option | Description | | --------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | | `-h, --help` | Show all available options. | | `[directory]` | A directory on which to analyze the application. If not provided, the current directory will be used. | | `--no-mangling` | Disables [mangling](https://en.wikipedia.org/wiki/Name_mangling). This may affect performance and should only be used for debugging purposes. | | `--profile` | Enables production [profiling for React](https://react.dev/reference/react/Profiler). This may affect performance. | | `-o, --output` | Write analysis files to disk without starting the server. Output is written to `.next/diagnostics/analyze`. | | `--port ` | Specify a port number to serve the analyzer on. (default: 4000, env: PORT) | ## Examples ### Debugging prerender errors If you encounter prerendering errors during `next build`, you can pass the `--debug-prerender` flag to get more detailed output: ```bash filename="Terminal" next build --debug-prerender ``` This enables several experimental options to make debugging easier: * Disables server code minification: * `experimental.serverMinification = false` * `experimental.turbopackMinify = false` * Generates source maps for server bundles: * `experimental.serverSourceMaps = true` * Enables source map consumption in child processes used for prerendering: * `enablePrerenderSourceMaps = true` * Continues building even after the first prerender error, so you can see all issues at once: * `experimental.prerenderEarlyExit = false` This helps surface more readable stack traces and code frames in the build output. > **Warning**: `--debug-prerender` is for debugging in development only. Do not deploy builds generated with `--debug-prerender` to production, as it may impact performance. ### Building specific routes You can build only specific routes in the App and Pages Routers using the `--debug-build-paths` option. This is useful for faster debugging when working with large applications. The `--debug-build-paths` option accepts comma-separated file paths and supports glob patterns: ```bash filename="Terminal" # Build a specific route next build --debug-build-paths="app/page.tsx" # Build more than one route next build --debug-build-paths="app/page.tsx,pages/index.tsx" # Use glob patterns next build --debug-build-paths="app/**/page.tsx" next build --debug-build-paths="pages/*.tsx" ``` ### Changing the default port By default, Next.js uses `http://localhost:3000` during development and with `next start`. The default port can be changed with the `-p` option, like so: ```bash filename="Terminal" next dev -p 4000 ``` Or using the `PORT` environment variable: ```bash filename="Terminal" PORT=4000 next dev ``` > **Good to know**: `PORT` cannot be set in `.env` as booting up the HTTP server happens before any other code is initialized. ### Using HTTPS during development For certain use cases like webhooks or authentication, you can use [HTTPS](https://developer.mozilla.org/en-US/docs/Glossary/HTTPS) to have a secure environment on `localhost`. Next.js can generate a self-signed certificate with `next dev` using the `--experimental-https` flag: ```bash filename="Terminal" next dev --experimental-https ``` With the generated certificate, the Next.js development server will exist at `https://localhost:3000`. The default port `3000` is used unless a port is specified with `-p`, `--port`, or `PORT`. You can also provide a custom certificate and key with `--experimental-https-key` and `--experimental-https-cert`. Optionally, you can provide a custom CA certificate with `--experimental-https-ca` as well. ```bash filename="Terminal" next dev --experimental-https --experimental-https-key ./certificates/localhost-key.pem --experimental-https-cert ./certificates/localhost.pem ``` `next dev --experimental-https` is only intended for development and creates a locally trusted certificate with [`mkcert`](https://github.com/FiloSottile/mkcert). In production, use properly issued certificates from trusted authorities. ### Configuring a timeout for downstream proxies When deploying Next.js behind a downstream proxy (e.g. a load-balancer like AWS ELB/ALB), it's important to configure Next's underlying HTTP server with [keep-alive timeouts](https://nodejs.org/api/http.html#http_server_keepalivetimeout) that are *larger* than the downstream proxy's timeouts. Otherwise, once a keep-alive timeout is reached for a given TCP connection, Node.js will immediately terminate that connection without notifying the downstream proxy. This results in a proxy error whenever it attempts to reuse a connection that Node.js has already terminated. To configure the timeout values for the production Next.js server, pass `--keepAliveTimeout` (in milliseconds) to `next start`, like so: ```bash filename="Terminal" next start --keepAliveTimeout 70000 ``` ### Passing Node.js arguments You can pass any [node arguments](https://nodejs.org/api/cli.html#cli_node_options_options) to `next` commands. For example: ```bash filename="Terminal" NODE_OPTIONS='--throw-deprecation' next NODE_OPTIONS='-r esm' next NODE_OPTIONS='--inspect' next ``` ### CPU profiling You can capture CPU profiles to analyze performance bottlenecks in your Next.js application. The `--experimental-cpu-prof` flag enables V8's built-in CPU profiler and saves profiles to `.next/cpu-profiles/` when the process exits: ```bash filename="Terminal" # Profile the build process next build --experimental-cpu-prof # Profile the dev server (profile saved on Ctrl+C or SIGTERM) next dev --experimental-cpu-prof # Profile the production server next start --experimental-cpu-prof ``` The generated `.cpuprofile` files can be opened in Chrome DevTools (Performance tab → Load profile) or other V8-compatible profiling tools. > **Good to know**: Profile files are named with a descriptive prefix and timestamp. The profiles generated depend on the command: > > **`next dev`:** > > * `dev-main-*` - Parent process (dev server orchestration) > * `dev-server-*` - Child server process (request handling and rendering) - this is typically what you want to analyze > > **`next build` (Turbopack):** > > * `build-main-*` - Main build orchestration process > * `build-turbopack-*` - Turbopack compilation worker > > **`next build` (Webpack):** > > * `build-main-*` - Main build orchestration process > * `build-webpack-client-*` - Client bundle compilation worker > * `build-webpack-server-*` - Server bundle compilation worker > * `build-webpack-edge-server-*` - Edge runtime compilation worker > > **`next start`:** > > * `start-main-*` - Production server process | Version | Changes | | --------- | ------------------------------------------------------------------------------- | | `v16.1.0` | Add the `next upgrade` command | | `v16.1.0` | Add the `next experimental-analyze` command | | `v16.0.0` | The JS bundle size metrics have been removed from `next build` | | `v15.5.0` | Add the `next typegen` command | | `v15.4.0` | Add `--debug-prerender` option for `next build` to help debug prerender errors. | --- For a semantic overview of all documentation, see [/docs/sitemap.md](/docs/sitemap.md) For an index of all available documentation, see [/docs/llms.txt](/docs/llms.txt)