CLI

The parcel CLI is the most common way to use Parcel. It supports several different commands: serve, watch, run, and build, as well as targets, trust, and help.

parcel serve <entries>

The serve command starts a development server, which will automatically rebuild your app as you change files, and supports hot reloading. It accepts one or more file paths or globs as entries.

parcel serve src/index.html

See Development for more details.

parcel watch <entries>

The watch command is similar to serve, but does not start a dev server. However, it automatically rebuilds your app as you make changes. Use watch if you're building a library, or have your own dev (HTTP) server. To build and run a Node.js backend, use parcel run (see below) instead. See below for how to specify entries.

parcel watch src/index.html

parcel run <entries>

The run command builds a Node.js entry in development mode, runs it with node, and automatically rebuilds it as you make changes. It supports hot reloading inside the running process: updates are applied in place when they are accepted via the module.hot API, and the process is restarted otherwise. With --no-hmr, the process is restarted whenever the code it runs changes. Code that is also loaded in the browser, such as client components rendered by the server, is hot reloaded in the browser as well.

The entry must be built for a Node.js environment, e.g. by specifying engines.node in your package.json. See Targets for details.

parcel run src/server.js

The process inherits the environment variables from your shell, and NODE_ENV is set to the same value used for the build (development unless you set it yourself). Variables loaded from .env files are inlined into the build, but are not passed to the process.

The HMR server used by run listens on a free port by default, so that it does not conflict with your own server. Use --hmr-port to choose a specific port.

parcel build <entries>

The build command performs a single production build and exits. This enables tree shaking and other production optimizations by default. See below for how to specify entries.

parcel build src/index.html

See Production for more details.

parcel targets <entries>

The targets command prints the entries and targets that Parcel resolves for the given entries, without building anything. This can be useful to debug your target configuration.

parcel targets

parcel trust

The trust command adds the local certificate authority that Parcel uses to sign certificates for --https to your system's trust stores, so that browsers trust them. Parcel also offers to do this the first time you use --https. Use --remove to remove it from the trust stores and delete it. See HTTPS for more details.

parcel trust

parcel help [command]

The help command shows help for all commands, or for a specific command. You can also pass -h or --help to any command.

Entries

All Parcel commands accept one or more entries. Entries may be relative or absolute paths, or globs. They may also be directories containing a package.json with a source field. If entries are omitted entirely, the source field in the package.json in the current working directory is used. See Entries in the Targets documentation for more details.

# Single file
parcel serve src/index.html

# Multiple files
parcel serve src/a.html src/b.html

# Glob (quotes required)
parcel serve 'src/*.html'

# Directory with package.json#source
parcel serve packages/frontend

# Multiple packages with a glob
parcel serve 'packages/*'

# Current directory with package.json#source
parcel serve

Parameters

These parameters are supported by all Parcel commands.

Parameters specific to serve and run

Parameters specific to serve

Parameters specific to run

Parameters specific to build