NODE(1)

NAME
node - server-side JavaScript runtime

SYNOPSIS
node [options] [v8-options] [-e string | script.js | -] [--] [arguments ...]
node inspect [-e string | script.js | | <host>:<port>] ...
node [--v8-options]

DESCRIPTION
Node.js is a set of libraries for JavaScript which allows it to be used outside of the browser. It is primarily focused on creating simple, easy-to-build network clients and servers.

Execute node without arguments to start a REPL.

OPTIONS

-   Alias for stdin, analogous to the use of - in other command-line utilities. The executed script is read from stdin, and remaining arguments are passed to the script.

--  Indicate the end of command-line options. Pass the rest of the arguments to the script.

    If no script filename or eval/print script is supplied prior to this, then the next argument will be used as a script filename.

--abort-on-uncaught-exception
    Aborting instead of exiting causes a core file to be generated for analysis.

--allow-fs-read
    Allow file system read access when using the permission model.

--allow-fs-write
    Allow file system write access when using the permission model.

--allow-addons
    Allow using native addons when using the permission model.

--allow-child-process
    Allow spawning process when using the permission model.

--allow-worker
    Allow creating worker threads when using the permission model.

--completion-bash
    Print source-able bash completion script for Node.js.

-C, --conditions string
    Use custom conditional exports conditions. string

--cpu-prof
    Start the V8 CPU profiler on start up, and write the CPU profile to disk before exit. If --cpu-prof-dir is not specified, the profile will be written to the current working directory with a generated file name.

--cpu-prof-dir
    The directory where the CPU profiles generated by --cpu-prof will be placed. The default value is controlled by the --diagnostic-dir. command-line option.

--cpu-prof-interval
    The sampling interval in microseconds for the CPU profiles generated by --cpu-prof. The default is 1000.

--cpu-prof-name
    File name of the V8 CPU profile generated with --cpu-prof.

--diagnostic-dir
    Set the directory for all diagnostic output files. Default is current working directory. Set the directory to which all diagnostic output files will be written to. Defaults to current working directory. Affects the default output directory of: --cpu-prof-dir. --heap-prof-dir. --redirect-warnings.

--disable-proto=mode
    Disable the `Object.prototype.__proto__` property. If mode is `delete`, the property will be removed entirely. If mode is `throw`, accesses to the property will throw an exception with the code `ERR_PROTO_ACCESS`.

--disable-wasm-trap-handler=mode
    Disable trap-handler-based WebAssembly bound checks and fall back to inline bound checks so that WebAssembly can be run with limited virtual memory.

--disallow-code-generation-from-strings
    Make built-in language features like `eval` and `new Function` that generate code from strings throw an exception instead. This does not affect the Node.js `vm` module.

--enable-fips
    Enable FIPS-compliant crypto at startup. Requires Node.js to be built with ./configure --openssl-fips.

--enable-source-maps
    Enable Source Map V3 support for stack traces.

--experimental-default-type=type
    Interpret as either ES modules or CommonJS modules input via --eval or STDIN, when --input-type is unspecified;

--experimental-import-meta-resolve
    Enable experimental ES modules support for import.meta.resolve().

--experimental-loader=module
    Specify the module to use as a custom module loader.

--experimental-network-imports
    Enable experimental support for loading modules using `import` over `https:`.

--experimental-permission
    Enable the experimental permission model.

--experimental-shadow-realm
    Use this flag to enable ShadowRealm support.

--experimental-test-coverage
    Enable code coverage in the test runner.

--experimental-eventsource
    Enable experimental support for the EventSource Web API.

--no-experimental-websocket
    Disable experimental support for the WebSocket API.

--no-experimental-repl-await
    Disable top-level await keyword support in REPL.

--experimental-vm-modules
    Enable experimental ES module support in VM module.

--experimental-wasi-unstable-preview1
    Enable experimental WebAssembly System Interface support. This flag is no longer required as WASI is enabled by default.

--experimental-wasm-modules
    Enable experimental WebAssembly module support.

--force-context-aware
    Disable loading native addons that are not context-aware.

--force-fips
    Force FIPS-compliant crypto on startup (Cannot be disabled from script code). Same requirements as --enable-fips.

--frozen-intrinsics
    Enable experimental frozen intrinsics support.

--heapsnapshot-near-heap-limit=max_count
    Generate heap snapshot when the V8 heap usage is approaching the heap limit. No more than the specified number of snapshots will be generated.

--heapsnapshot-signal=signal
    Generate heap snapshot on specified signal.

--heap-prof
    Start the V8 heap profiler on start up, and write the heap profile to disk before exit. If --heap-prof-dir is not specified, the profile will be written to the current working directory with a generated file name.

--heap-prof-dir
    The directory where the heap profiles generated by --heap-prof will be placed. The default value is controlled by the --diagnostic-dir. command-line option.

--heap-prof-interval
    The average sampling interval in bytes for the heap profiles generated by --heap-prof. The default is 512 * 1024.

--heap-prof-name
    File name of the V8 heap profile generated with --heap-prof.

--icu-data-dir=file
    Specify ICU data load path. Overrides NODE_ICU_DATA.

--input-type=type
    Set the module resolution type for input via --eval, --print or STDIN.

--inspect-brk=[host:]port
    Activate inspector on host:port and break at start of user script.

--inspect-port=[host:]port
    Set the host:port to be used when the inspector is activated.

--inspect-publish-uid=stderr,http
    Specify how the inspector WebSocket URL is exposed. Valid values are stderr and http. Default is stderr,http.

--inspect-wait=[host:]port
    Activate inspector on host:port and wait for debugger to be attached.

--inspect=[host:]port
    Activate inspector on host:port. Default is 127.0.0.1:9229.

    V8 Inspector integration allows attaching Chrome DevTools and IDEs to Node.js instances for debugging and profiling. It uses the Chrome DevTools Protocol.

--insecure-http-parser
    Use an insecure HTTP parser that accepts invalid HTTP headers. This may allow interoperability with non-conformant HTTP implementations. It may also allow request smuggling and other HTTP attacks that rely on invalid headers being accepted. Avoid using this option.

--jitless
    Disable runtime allocation of executable memory. This may be required on some platforms for security reasons. It can also reduce attack surface on other platforms, but the performance impact may be severe.

    This flag is inherited from V8 and is subject to change upstream. It may disappear in a non-semver-major release.

--max-http-header-size=size
    Specify the maximum size of HTTP headers in bytes. Defaults to 16 KiB.

--napi-modules
    This option is a no-op. It is kept for compatibility.

--no-deprecation
    Silence deprecation warnings.

--no-extra-info-on-fatal-exception
    Hide extra information on fatal exception that causes exit.

--no-force-async-hooks-checks
    Disable runtime checks for `async_hooks`. These will still be enabled dynamically when `async_hooks` is enabled.

--no-addons
    Disable the `node-addons` exports condition as well as disable loading native addons. When `--no-addons` is specified, calling `process.dlopen` or requiring a native C++ addon will fail and throw an exception.

--no-global-search-paths
    Do not search modules from global paths.

--no-warnings
    Silence all process warnings (including deprecations).

--node-memory-debug
    Enable extra debug checks for memory leaks in Node.js internals. This is usually only useful for developers debugging Node.js itself.

--openssl-config=file
    Load an OpenSSL configuration file on startup. Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is built with ./configure --openssl-fips.

--pending-deprecation
    Emit pending deprecation warnings.

--preserve-symlinks
    Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.

--preserve-symlinks-main
    Instructs the module loader to preserve symbolic links when resolving and caching the main module.

--prof
    Generate V8 profiler output.

--prof-process
    Process V8 profiler output generated using the V8 option --prof.

--redirect-warnings=file
    Write process warnings to the given file instead of printing to stderr.

--report-compact
    Write diagnostic reports in a compact format, single-line JSON.

--report-dir --report-directory
    Location at which the diagnostic report will be generated. The `file` name may be an absolute path. If it is not, the default directory it will be written to is controlled by the --diagnostic-dir. command-line option.

--report-filename
    Name of the file to which the diagnostic report will be written.

--report-on-fatalerror
    Enables the diagnostic report to be triggered on fatal errors (internal errors within the Node.js runtime such as out of memory) that leads to termination of the application. Useful to inspect various diagnostic data elements such as heap, stack, event loop state, resource consumption etc. to reason about the fatal error.

--report-on-signal
    Enables diagnostic report to be generated upon receiving the specified (or predefined) signal to the running Node.js process. Default signal is SIGUSR2.

--report-signal
    Sets or resets the signal for diagnostic report generation (not supported on Windows). Default signal is SIGUSR2.

--report-uncaught-exception
    Enables diagnostic report to be generated on un-caught exceptions. Useful when inspecting JavaScript stack in conjunction with native stack and other runtime environment data.

--secure-heap=n
    Specify the size of the OpenSSL secure heap. Any value less than 2 disables the secure heap. The default is 0. The value must be a power of two.

--secure-heap-min=n
    Specify the minimum allocation from the OpenSSL secure heap. The default is 2. The value must be a power of two.

--test
    Starts the Node.js command line test runner.

--test-concurrency
    The maximum number of test files that the test runner CLI will execute concurrently.

--test-force-exit
    Configures the test runner to exit the process once all known tests have finished executing even if the event loop would otherwise remain active.

--test-name-pattern
    A regular expression that configures the test runner to only execute tests whose name matches the provided pattern.

--test-reporter
    A test reporter to use when running tests.

--test-reporter-destination
    The destination for the corresponding test reporter.

--test-only
    Configures the test runner to only execute top level tests that have the `only` option set.

--test-shard
    Test suite shard to execute in a format of <index>/<total>.

--test-skip-pattern
    A regular expression that configures the test runner to skip tests whose name matches the provided pattern.

--test-timeout
    A number of milliseconds the test execution will fail after.

--throw-deprecation
    Throw errors for deprecations.

--title=title
    Specify process.title on startup.

--tls-cipher-list=list
    Specify an alternative default TLS cipher list. Requires Node.js to be built with crypto support. (Default)

--tls-keylog=file
    Log TLS key material to a file. The key material is in NSS SSLKEYLOGFILE format and can be used by software (such as Wireshark) to decrypt the TLS traffic.

--tls-max-v1.2
    Set default maxVersion to 'TLSv1.2'. Use to disable support for TLSv1.3.

--tls-max-v1.3
    Set default maxVersion to 'TLSv1.3'. Use to enable support for TLSv1.3.

--tls-min-v1.0
    Set default minVersion to 'TLSv1'. Use for compatibility with old TLS clients or servers.

--tls-min-v1.1
    Set default minVersion to 'TLSv1.1'. Use for compatibility with old TLS clients or servers.

--tls-min-v1.2
    Set default minVersion to 'TLSv1.2'. This is the default for 12.x and later, but the option is supported for compatibility with older Node.js versions.

--tls-min-v1.3
    Set default minVersion to 'TLSv1.3'. Use to disable support for TLSv1.2 in favour of TLSv1.3, which is more secure.

--trace-deprecation
    Print stack traces for deprecations.

--trace-event-categories categories
    A comma-separated list of categories that should be traced when trace event tracing is enabled using --trace-events-enabled.

--trace-event-file-pattern pattern
    Template string specifying the filepath for the trace event data, it supports ${rotation} and ${pid}.

--trace-events-enabled
    Enable the collection of trace event tracing information.

--trace-exit
    Prints a stack trace whenever an environment is exited proactively, i.e. invoking `process.exit()`.

--trace-sigint
    Prints a stack trace on SIGINT.

--trace-sync-io
    Print a stack trace whenever synchronous I/O is detected after the first turn of the event loop.

--trace-tls
    Prints TLS packet trace information to stderr.

--trace-uncaught
    Print stack traces for uncaught exceptions; usually, the stack trace associated with the creation of an Error is printed, whereas this makes Node.js also print the stack trace associated with throwing the value (which does not need to be an Error instance).

    Enabling this option may affect garbage collection behavior negatively.

--trace-warnings
    Print stack traces for process warnings (including deprecations).

--track-heap-objects
    Track heap object allocations for heap snapshots.

--unhandled-rejections=mode
    Define the behavior for unhandled rejections. Can be one of `strict` (raise an error), `warn` (enforce warnings) or `none` (silence warnings).

--use-bundled-ca, --use-openssl-ca
    Use bundled Mozilla CA store as supplied by current Node.js version or use OpenSSL's default CA store. The default store is selectable at build-time.

    The bundled CA store, as supplied by Node.js, is a snapshot of Mozilla CA store that is fixed at release time. It is identical on all supported platforms.

    Using OpenSSL store allows for external modifications of the store. For most Linux and BSD distributions, this store is maintained by the distribution maintainers and system administrators. OpenSSL CA store location is dependent on configuration of the OpenSSL library but this can be altered at runtime using environment variables.

    See SSL_CERT_DIR and SSL_CERT_FILE.

--use-largepages=mode
    Re-map the Node.js static code to large memory pages at startup. If supported on the target system, this will cause the Node.js static code to be moved onto 2 MiB pages instead of 4 KiB pages.

    mode must have one of the following values: `off` (the default value, meaning do not map), `on` (map and ignore failure, reporting it to stderr), or `silent` (map and silently ignore failure).

--v8-options
    Print V8 command-line options.

--v8-pool-size=num
    Set V8's thread pool size which will be used to allocate background jobs. If set to 0 then V8 will choose an appropriate size of the thread pool based on the number of online processors. If the value provided is larger than V8's maximum, then the largest value will be chosen.

--zero-fill-buffers
    Automatically zero-fills all newly allocated Buffer and SlowBuffer instances.

-c, --check
    Check the script's syntax without executing it. Exits with an error code if script is invalid.

-e, --eval string
    Evaluate string as JavaScript.

-h, --help
    Print command-line options. The output of this option is less detailed than this document.

-i, --interactive
    Open the REPL even if stdin does not appear to be a terminal.

-p, --print string
    Identical to -e, but prints the result.

-r, --require module
    Preload the specified module at startup. Follows `require()`'s module resolution rules. module may be either a path to a file, or a Node.js module name.

-v, --version
    Print node's version.

ENVIRONMENT

FORCE_COLOR
    Used to enable ANSI colorized output. The value may be one of: 1 , true , or an empty string to indicate 16-color support, 2 to indicate 256-color support, or 3 to indicate 16 million-color support. When used and set to a supported value, both the NO_COLOR and NODE_DISABLE_COLORS environment variables are ignored. Any other value will result in colorized output being disabled.

NO_COLOR
    Alias for NODE_DISABLE_COLORS

NODE_DEBUG modules...
    Comma-separated list of core modules that should print debug information.

NODE_DEBUG_NATIVE modules...
    Comma-separated list of C++ core modules that should print debug information.

NODE_DISABLE_COLORS
    When set to 1, colors will not be used in the REPL.

NODE_EXTRA_CA_CERTS file
    When set, the well-known “root” CAs (like VeriSign) will be extended with the extra certificates in file. The file should consist of one or more trusted certificates in PEM format.

    If file is missing or misformatted, a message will be emitted once using process.emitWarning(), but any errors are otherwise ignored.

    This environment variable is ignored when `node` runs as setuid root or has Linux file capabilities set.

    The NODE_EXTRA_CA_CERTS environment variable is only read when the Node.js process is first launched. Changing the value at runtime using process.env.NODE_EXTRA_CA_CERTS has no effect on the current process.

NODE_ICU_DATA file
    Data path for ICU (Intl object) data. Will extend linked-in data when compiled with small-icu support.

NODE_NO_WARNINGS
    When set to 1, process warnings are silenced.

NODE_OPTIONS options...
    A space-separated list of command-line options, which are interpreted as if they had been specified on the command line before the actual command (so they can be overridden). Node.js will exit with an error if an option that is not allowed in the environment is used, such as --print or a script file.

NODE_PATH directories...
    A colon-separated list of directories prefixed to the module search path.

NODE_PENDING_DEPRECATION
    When set to 1, emit pending deprecation warnings.

NODE_PRESERVE_SYMLINKS
    When set to 1, the module loader preserves symbolic links when resolving and caching modules.

NODE_REDIRECT_WARNINGS file
    Write process warnings to the given file instead of printing to stderr. Equivalent to passing --redirect-warnings file on the command line.

NODE_REPL_HISTORY file
    Path to the file used to store persistent REPL history. The default path is ~/.node_repl_history, which is overridden by this variable. Setting the value to an empty string ("" or " ") will disable persistent REPL history.

NODE_REPL_EXTERNAL_MODULE file
    Path to a Node.js module which will be loaded in place of the built-in REPL. Overriding this value to an empty string (`''`) will use the built-in REPL.

NODE_SKIP_PLATFORM_CHECK
    When set to 1, the check for a supported platform is skipped during Node.js startup. Node.js might not execute correctly. Any issues encountered on unsupported platforms will not be fixed.

NODE_TLS_REJECT_UNAUTHORIZED
    When set to 0, TLS certificate validation is disabled.

NODE_V8_COVERAGE dir
    When set, Node.js writes JavaScript code coverage information to dir.

OPENSSL_CONF file
    Load an OpenSSL configuration file on startup. Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is built with ./configure --openssl-fips.

    If the --openssl-config command-line option is used, this environment variable is ignored.

SSL_CERT_DIR dir
    If --use-openssl-ca is enabled, this overrides and sets OpenSSL's directory containing trusted certificates.

SSL_CERT_FILE file
    If --use-openssl-ca is enabled, this overrides and sets OpenSSL's file containing trusted certificates.

TZ  Specify the timezone configuration.

UV_THREADPOOL_SIZE size
    Sets the number of threads used in libuv's threadpool to size.

BUGS
Bugs are tracked in GitHub Issues: https://github.com/nodejs/node/issues

COPYRIGHT
Copyright Node.js contributors. Node.js is available under the MIT license.

Node.js also includes external libraries that are available under a variety of licenses. See https://github.com/nodejs/node/blob/HEAD/LICENSE for the full license text.

SEE ALSO
Website: https://nodejs.org/

Documentation: https://nodejs.org/api/

GitHub repository and issue tracker: https://github.com/nodejs/node

IRC (general questions): libera.chat #node.js (unofficial)