This plugin enables more fine grained control of source map generation. It is also enabled automatically by certain settings of the devtool configuration option.

new webpack.SourceMapDevToolPlugin(options);


The following options are supported:

  • test (string RegExp [string, RegExp]): Include source maps for modules based on their extension (defaults to .js, .mjs, and .css).
  • include (string RegExp [string, RegExp]): Include source maps for module paths that match the given value.
  • exclude (string RegExp [string, RegExp]): Exclude modules that match the given value from source map generation.
  • filename (string): Defines the output filename of the SourceMap (will be inlined if no value is provided).
  • append (string): Appends the given value to the original asset. Usually the #sourceMappingURL comment. [url] is replaced with a URL to the source map file. Since webpack v4.36.0, path parameters are supported: [chunk], [filename] and [contenthash]. Setting append to false disables the appending.
  • moduleFilenameTemplate (string): See output.devtoolModuleFilenameTemplate.
  • fallbackModuleFilenameTemplate (string): See link above.
  • namespace (string): See output.devtoolNamespace.
  • module = true (boolean): Indicates whether loaders should generate source maps.
  • columns = true (boolean): Indicates whether column mappings should be used.
  • noSources = false (boolean): Prevents the source file content from being included in the source map.
  • publicPath (string): Emits absolute URLs with public path prefix, e.g.
  • fileContext (string): Makes the [file] argument relative to this directory.
  • sourceRoot (string): Provide a custom value for the sourceRoot property in the SourceMap.

The fileContext option is useful when you want to store source maps in an upper level directory to avoid ../../ appearing in the absolute [url].

Setting module and/or columns to false will yield less accurate source maps but will also improve compilation performance significantly.

If you want to use a custom configuration for this plugin in development mode, make sure to disable the default one. I.e. set devtool: false.

If the default webpack minimizer has been overridden (such as to customise the TerserPlugin options), make sure to configure its replacement with sourceMap: true to enable SourceMap support.


The following examples demonstrate some common use cases for this plugin.

Basic Use Case

You can use the following code to replace the configuration option devtool: inline-source-map with an equivalent custom plugin configuration:

module.exports = {
  // ...
  devtool: false,
  plugins: [
    new webpack.SourceMapDevToolPlugin({})

Exclude Vendor Maps

The following code would exclude source maps for any modules in the vendor.js bundle:

new webpack.SourceMapDevToolPlugin({
  filename: '[name]',
  exclude: ['vendor.js']

Host Source Maps Externally

Set a URL for source maps. Useful for hosting them on a host that requires authorization.

new webpack.SourceMapDevToolPlugin({
  append: '\n//# sourceMappingURL=[url]',
  filename: '[name].map'

And for cases when source maps are stored in the upper level directory:

|- dist
  |- public
    |- bundle-[hash].js
  |- sourcemaps
    |- bundle-[hash]

With next config:

new webpack.SourceMapDevToolPlugin({
  filename: 'sourcemaps/[file].map',
  publicPath: '',
  fileContext: 'public'

Will produce the following URL:[hash]