Metro CLI Options

The metro command line runner has a number of useful options. You can run metro --help to view all available options. Here is a brief overview:

build <entry>

Generates a JavaScript bundle containing the specified entrypoint and its descendants.


outOFile name where to store the outputString
platformpWhich platform to bundle forweb, android, ios
minifyzWhether Metro should minify the bundleBoolean
devgCreate a development version of the build (process.env.NODE_ENV = 'development')Boolean
configcLocation of the metro.config.js to useString
max-workersjThe number of workers Metro should parallelize the transformer onNumber
project-rootsPThe root folder of your projectArray
source-mapWhether Metro should generate source mapsBoolean
source-map-urlURL where the source map can be foundString
legacy-bundlerWhether Metro should use the legacy bundlerBoolean


Starts Metro on the given port, building bundles on the fly.


Lists dependencies.


entry-fileAbsolute path to the root JS file
outputFile name where to store the output, ex. /tmp/dependencies.txt
platformThe platform extension used for selecting modules
transformerSpecify a custom transformer to be used
max-workersSpecifies the maximum number of workers the worker-pool will spawn for transforming files. This defaults to the number of the cores available on your machine.
devIf false, skip all dev-only code path
verboseEnables logging