--- title: next CLI description: Learn how to run and build your application with the Next.js CLI. url: "https://nextjs.org/docs/15/app/api-reference/cli/next" version: 15.5.15 lastUpdated: 2025-09-23 prerequisites: - "API Reference: /docs/15/app/api-reference" - "CLI: /docs/15/app/api-reference/cli" --- The Next.js CLI allows you to develop, build, start your application, and more. Basic usage: ```bash filename="Terminal" npx next [command] [options] ``` ## 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. | | [`lint`](#next-lint-options) | Runs ESLint for all files in the `/src`, `/app`, `/pages`, `/components`, and `/lib` directories. It also provides a guided setup to install any required dependencies if ESLint it is not already configured in your application. | | [`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. | > **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. 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` | Starts development mode using [Turbopack](/docs/app/api-reference/turbopack). Also available as `--turbo`. | | `-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. | ### `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) Size First Load JS ┌ ○ /_not-found 0 B 0 kB └ ƒ /products/[id] 0 B 0 kB ○ (Static) prerendered as static content ƒ (Dynamic) server-rendered on demand ``` * **Size**: The size of assets downloaded when navigating to the page client-side. The size for each route only includes its dependencies. * **First Load JS**: The size of assets downloaded when visiting the page from the server. The amount of JS shared by all is shown as a separate metric. Both of these values are [**compressed with gzip**](/docs/app/api-reference/config/next-config-js/compress). The first load is indicated by green, yellow, or red. Aim for green for performant applications. 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` | Build using [Turbopack](/docs/app/api-reference/turbopack) (beta). Also available as `--turbo`. | | `-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. | ### `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. | ### `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 lint` options > **Warning**: This option is deprecated and will be removed in Next 16. A [codemod](/blog/next-15-5#next-lint-deprecation) is available to migrate to ESLint CLI. `next lint` runs ESLint for all files in the `pages/`, `app/`, `components/`, `lib/`, and `src/` directories. It also provides a guided setup to install any required dependencies if ESLint is not already configured in your application. The following options are available for the `next lint` command: | Option | Description | | ----------------------------------------------------- | ------------------------------------------------------------------------------------------------------------- | | `[directory]` | A base directory on which to lint the application. If not provided, the current directory will be used. | | `-d, --dir, ` | Include directory, or directories, to run ESLint. | | `--file, ` | Include file, or files, to run ESLint. | | `--ext, [exts...]` | Specify JavaScript file extensions. (default: \[".js", ".mjs", ".cjs", ".jsx", ".ts", ".mts", ".cts", ".tsx"]) | | `-c, --config, ` | Uses this configuration file, overriding all other configuration options. | | `--resolve-plugins-relative-to, ` | Specify a directory where plugins should be resolved from. | | `--strict` | Creates a `.eslintrc.json` file using the Next.js strict configuration. | | `--rulesdir, ` | Uses additional rules from this directory(s). | | `--fix` | Automatically fix linting issues. | | `--fix-type ` | Specify the types of fixes to apply (e.g., problem, suggestion, layout). | | `--ignore-path ` | Specify a file to ignore. | | `--no-ignore ` | Disables the `--ignore-path` option. | | `--quiet` | Reports errors only. | | `--max-warnings [maxWarnings]` | Specify the number of warnings before triggering a non-zero exit code. (default: -1) | | `-o, --output-file, ` | Specify a file to write report to. | | `-f, --format, ` | Uses a specific output format. | | `--no-inline-config` | Prevents comments from changing config or rules. | | `--report-unused-disable-directives-severity ` | Specify severity level for unused eslint-disable directives. (choices: "error", "off", "warn") | | `--no-cache` | Disables caching. | | `--cache-location, ` | Specify a location for cache. | | `--cache-strategy, [cacheStrategy]` | Specify a strategy to use for detecting changed files in the cache. (default: "metadata") | | `--error-on-unmatched-pattern` | Reports errors when any file patterns are unmatched. | | `-h, --help` | Displays this message. | ### `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` (default: `.next/types`): ```bash filename="Terminal" next typegen # or for a specific app next typegen ./apps/web ``` > **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. ## 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: * `experimental.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. ### 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 ``` | Version | Changes | | --------- | ------------------------------------------------------------------------------- | | `v15.5.0` | Add the `next typegen` command | | `v15.4.0` | Add `--debug-prerender` option for `next build` to help debug prerender errors. | --- For an index of all available documentation, see [/docs/15/llms.txt](/docs/15/llms.txt)