These options allows you to control how webpack notifies you of assets and entry points that exceed a specific file limit. This feature was inspired by the idea of webpack Performance Budgets.

performance

object

Configure how performance hints are shown. For example if you have an asset that is over 250kb, webpack will emit a warning notifying you of this.

performance.assetFilter

function(assetFilename) => boolean

This property allows webpack to control what files are used to calculate performance hints. The default function is:

function assetFilter(assetFilename) {
  return !/\.map$/.test(assetFilename);
}

You can override this property by passing your own function in:

module.exports = {
  //...
  performance: {
    assetFilter: function (assetFilename) {
      return assetFilename.endsWith('.js');
    },
  },
};

The example above will only give you performance hints based on .js files.

performance.hints

string = 'warning': 'error' | 'warning' boolean: false

Turns hints on/off. In addition, tells webpack to throw either an error or a warning when hints are found.

Given an asset is created that is over 250kb:

module.exports = {
  //...
  performance: {
    hints: false,
  },
};

No hint warnings or errors are shown.

module.exports = {
  //...
  performance: {
    hints: 'warning',
  },
};

A warning will be displayed notifying you of a large asset. We recommend something like this for development environments.

module.exports = {
  //...
  performance: {
    hints: 'error',
  },
};

An error will be displayed notifying you of a large asset. We recommend using hints: "error" during production builds to help prevent deploying production bundles that are too large, impacting webpage performance.

performance.maxAssetSize

number = 250000

An asset is any emitted file from webpack. This option controls when webpack emits a performance hint based on individual asset size in bytes.

module.exports = {
  //...
  performance: {
    maxAssetSize: 100000,
  },
};

performance.maxEntrypointSize

number = 250000

An entry point represents all assets that would be utilized during initial load time for a specific entry. This option controls when webpack should emit performance hints based on the maximum entry point size in bytes.

module.exports = {
  //...
  performance: {
    maxEntrypointSize: 400000,
  },
};