Socket
Socket
Sign inDemoInstall

terser-webpack-plugin

Package Overview
Dependencies
76
Maintainers
3
Versions
77
Alerts
File Explorer

Advanced tools

Install Socket

Detect and block malicious and high-risk dependencies

Install

terser-webpack-plugin

Terser plugin for webpack


Version published
Maintainers
3
Weekly downloads
26,271,743
decreased by-9.19%

Weekly downloads

Package description

What is terser-webpack-plugin?

The terser-webpack-plugin is a plugin for webpack that uses Terser to minify JavaScript files. It can improve the performance of web applications by reducing the size of the JavaScript bundle, which decreases loading times for users. It also offers options for code compression, mangling, and potentially other optimizations that can be configured to suit various deployment needs.

What are terser-webpack-plugin's main functionalities?

Minification

This feature allows you to minify your JavaScript files, removing unnecessary whitespace, comments, and code. It helps in reducing the file size and improving load times for your web application.

const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin()],
  },
};

Source Map Support

This feature enables the generation of source maps, which help in debugging minified JavaScript by mapping the minified code back to the original source code.

const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin({
      sourceMap: true,
    })],
  },
};

Code Compression

This feature allows for further compression of the JavaScript code, such as removing console logs and other statements that are not needed in production code.

const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin({
      terserOptions: {
        compress: {
          drop_console: true,
        },
      },
    })],
  },
};

Mangling

Mangling reduces the size of your code by shortening the names of variables and functions to single characters. This feature is particularly useful for reducing the size of large codebases.

const TerserPlugin = require('terser-webpack-plugin');

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin({
      terserOptions: {
        mangle: true, // Note: `mangle` is `true` by default.
      },
    })],
  },
};

Other packages similar to terser-webpack-plugin

Readme

Source

npm node tests cover discussion size

terser-webpack-plugin

This plugin uses terser to minify/minimize your JavaScript.

Getting Started

Webpack v5 comes with the latest terser-webpack-plugin out of the box. If you are using Webpack v5 or above and wish to customize the options, you will still need to install terser-webpack-plugin. Using Webpack v4, you have to install terser-webpack-plugin v4.

To begin, you'll need to install terser-webpack-plugin:

npm install terser-webpack-plugin --save-dev

or

yarn add -D terser-webpack-plugin

or

pnpm add -D terser-webpack-plugin

Then add the plugin to your webpack config. For example:

webpack.config.js

const TerserPlugin = require("terser-webpack-plugin");

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin()],
  },
};

And run webpack via your preferred method.

Note about source maps

Works only with source-map, inline-source-map, hidden-source-map and nosources-source-map values for the devtool option.

Why?

  • eval wraps modules in eval("string") and the minimizer does not handle strings.
  • cheap has not column information and minimizer generate only a single line, which leave only a single mapping.

Using supported devtool values enable source map generation.

Options

test

Type:

type test = string | RegExp | Array<string | RegExp>;

Default: /\.m?js(\?.*)?$/i

Test to match files against.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        test: /\.js(\?.*)?$/i,
      }),
    ],
  },
};

include

Type:

type include = string | RegExp | Array<string | RegExp>;

Default: undefined

Files to include.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        include: /\/includes/,
      }),
    ],
  },
};

exclude

Type:

type exclude = string | RegExp | Array<string | RegExp>;

Default: undefined

Files to exclude.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        exclude: /\/excludes/,
      }),
    ],
  },
};

parallel

Type:

type parallel = boolean | number;

Default: true

Use multi-process parallel running to improve the build speed. Default number of concurrent runs: os.cpus().length - 1.

Note

Parallelization can speedup your build significantly and is therefore highly recommended.

Warning

If you use Circle CI or any other environment that doesn't provide real available count of CPUs then you need to setup explicitly number of CPUs to avoid Error: Call retries were exceeded (see #143, #202).

boolean

Enable/disable multi-process parallel running.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        parallel: true,
      }),
    ],
  },
};
number

Enable multi-process parallel running and set number of concurrent runs.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        parallel: 4,
      }),
    ],
  },
};

minify

Type:

type minify = (
  input: {
    [file: string]: string;
  },
  sourceMap: import("@jridgewell/trace-mapping").SourceMapInput | undefined,
  minifyOptions: {
    module?: boolean | undefined;
    ecma?: import("terser").ECMA | undefined;
  },
  extractComments:
    | boolean
    | "all"
    | "some"
    | RegExp
    | ((
        astNode: any,
        comment: {
          value: string;
          type: "comment1" | "comment2" | "comment3" | "comment4";
          pos: number;
          line: number;
          col: number;
        }
      ) => boolean)
    | {
        condition?:
          | boolean
          | "all"
          | "some"
          | RegExp
          | ((
              astNode: any,
              comment: {
                value: string;
                type: "comment1" | "comment2" | "comment3" | "comment4";
                pos: number;
                line: number;
                col: number;
              }
            ) => boolean)
          | undefined;
        filename?: string | ((fileData: any) => string) | undefined;
        banner?:
          | string
          | boolean
          | ((commentsFile: string) => string)
          | undefined;
      }
    | undefined
) => Promise<{
  code: string;
  map?: import("@jridgewell/trace-mapping").SourceMapInput | undefined;
  errors?: (string | Error)[] | undefined;
  warnings?: (string | Error)[] | undefined;
  extractedComments?: string[] | undefined;
}>;

Default: TerserPlugin.terserMinify

Allows you to override default minify function. By default plugin uses terser package. Useful for using and testing unpublished versions or forks.

Warning

Always use require inside minify function when parallel option enabled.

webpack.config.js

// Can be async
const minify = (input, sourceMap, minimizerOptions, extractsComments) => {
  // The `minimizerOptions` option contains option from the `terserOptions` option
  // You can use `minimizerOptions.myCustomOption`

  // Custom logic for extract comments
  const { map, code } = require("uglify-module") // Or require('./path/to/uglify-module')
    .minify(input, {
      /* Your options for minification */
    });

  return { map, code, warnings: [], errors: [], extractedComments: [] };
};

// Used to regenerate `fullhash`/`chunkhash` between different implementation
// Example: you fix a bug in custom minimizer/custom function, but unfortunately webpack doesn't know about it, so you will get the same fullhash/chunkhash
// to avoid this you can provide version of your custom minimizer
// You don't need if you use only `contenthash`
minify.getMinimizerVersion = () => {
  let packageJson;

  try {
    // eslint-disable-next-line global-require, import/no-extraneous-dependencies
    packageJson = require("uglify-module/package.json");
  } catch (error) {
    // Ignore
  }

  return packageJson && packageJson.version;
};

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          myCustomOption: true,
        },
        minify,
      }),
    ],
  },
};

terserOptions

Type:

type terserOptions = {
  compress?: boolean | CompressOptions;
  ecma?: ECMA;
  enclose?: boolean | string;
  ie8?: boolean;
  keep_classnames?: boolean | RegExp;
  keep_fnames?: boolean | RegExp;
  mangle?: boolean | MangleOptions;
  module?: boolean;
  nameCache?: object;
  format?: FormatOptions;
  /** @deprecated */
  output?: FormatOptions;
  parse?: ParseOptions;
  safari10?: boolean;
  sourceMap?: boolean | SourceMapOptions;
  toplevel?: boolean;
};

Default: default

Terser options.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          ecma: undefined,
          parse: {},
          compress: {},
          mangle: true, // Note `mangle.properties` is `false` by default.
          module: false,
          // Deprecated
          output: null,
          format: null,
          toplevel: false,
          nameCache: null,
          ie8: false,
          keep_classnames: undefined,
          keep_fnames: false,
          safari10: false,
        },
      }),
    ],
  },
};

extractComments

Type:

type extractComments =
  | boolean
  | string
  | RegExp
  | ((
      astNode: any,
      comment: {
        value: string;
        type: "comment1" | "comment2" | "comment3" | "comment4";
        pos: number;
        line: number;
        col: number;
      }
    ) => boolean)
  | {
      condition?:
        | boolean
        | "all"
        | "some"
        | RegExp
        | ((
            astNode: any,
            comment: {
              value: string;
              type: "comment1" | "comment2" | "comment3" | "comment4";
              pos: number;
              line: number;
              col: number;
            }
          ) => boolean)
        | undefined;
      filename?: string | ((fileData: any) => string) | undefined;
      banner?:
        | string
        | boolean
        | ((commentsFile: string) => string)
        | undefined;
    };

Default: true

Whether comments shall be extracted to a separate file, (see details). By default extract only comments using /^\**!|@preserve|@license|@cc_on/i regexp condition and remove remaining comments. If the original file is named foo.js, then the comments will be stored to foo.js.LICENSE.txt. The terserOptions.format.comments option specifies whether the comment will be preserved, i.e. it is possible to preserve some comments (e.g. annotations) while extracting others or even preserving comments that have been extracted.

boolean

Enable/disable extracting comments.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: true,
      }),
    ],
  },
};
string

Extract all or some (use /^\**!|@preserve|@license|@cc_on/i RegExp) comments.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: "all",
      }),
    ],
  },
};
RegExp

All comments that match the given expression will be extracted to the separate file.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: /@extract/i,
      }),
    ],
  },
};
function

All comments that match the given expression will be extracted to the separate file.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: (astNode, comment) => {
          if (/@extract/i.test(comment.value)) {
            return true;
          }

          return false;
        },
      }),
    ],
  },
};
object

Allow to customize condition for extract comments, specify extracted file name and banner.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: {
          condition: /^\**!|@preserve|@license|@cc_on/i,
          filename: (fileData) => {
            // The "fileData" argument contains object with "filename", "basename", "query" and "hash"
            return `${fileData.filename}.LICENSE.txt${fileData.query}`;
          },
          banner: (licenseFile) => {
            return `License information can be found in ${licenseFile}`;
          },
        },
      }),
    ],
  },
};
condition

Type:

type condition =
  | boolean
  | "all"
  | "some"
  | RegExp
  | ((
      astNode: any,
      comment: {
        value: string;
        type: "comment1" | "comment2" | "comment3" | "comment4";
        pos: number;
        line: number;
        col: number;
      }
    ) => boolean)
  | undefined;

Condition what comments you need extract.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: {
          condition: "some",
          filename: (fileData) => {
            // The "fileData" argument contains object with "filename", "basename", "query" and "hash"
            return `${fileData.filename}.LICENSE.txt${fileData.query}`;
          },
          banner: (licenseFile) => {
            return `License information can be found in ${licenseFile}`;
          },
        },
      }),
    ],
  },
};
filename

Type:

type filename = string | ((fileData: any) => string) | undefined;

Default: [file].LICENSE.txt[query]

Available placeholders: [file], [query] and [filebase] ([base] for webpack 5).

The file where the extracted comments will be stored. Default is to append the suffix .LICENSE.txt to the original filename.

Warning

We highly recommend using the txt extension. Using js/cjs/mjs extensions may conflict with existing assets which leads to broken code.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: {
          condition: /^\**!|@preserve|@license|@cc_on/i,
          filename: "extracted-comments.js",
          banner: (licenseFile) => {
            return `License information can be found in ${licenseFile}`;
          },
        },
      }),
    ],
  },
};
banner

Type:

type banner = string | boolean | ((commentsFile: string) => string) | undefined;

Default: /*! For license information please see ${commentsFile} */

The banner text that points to the extracted file and will be added on top of the original file. Can be false (no banner), a String, or a Function<(string) -> String> that will be called with the filename where extracted comments have been stored. Will be wrapped into comment.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        extractComments: {
          condition: true,
          filename: (fileData) => {
            // The "fileData" argument contains object with "filename", "basename", "query" and "hash"
            return `${fileData.filename}.LICENSE.txt${fileData.query}`;
          },
          banner: (commentsFile) => {
            return `My custom banner about license information ${commentsFile}`;
          },
        },
      }),
    ],
  },
};

Examples

Preserve Comments

Extract all legal comments (i.e. /^\**!|@preserve|@license|@cc_on/i) and preserve /@license/i comments.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          format: {
            comments: /@license/i,
          },
        },
        extractComments: true,
      }),
    ],
  },
};

Remove Comments

If you avoid building with comments, use this config:

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          format: {
            comments: false,
          },
        },
        extractComments: false,
      }),
    ],
  },
};

uglify-js

UglifyJS is a JavaScript parser, minifier, compressor and beautifier toolkit.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        minify: TerserPlugin.uglifyJsMinify,
        // `terserOptions` options will be passed to `uglify-js`
        // Link to options - https://github.com/mishoo/UglifyJS#minify-options
        terserOptions: {},
      }),
    ],
  },
};

swc

swc is a super-fast compiler written in rust; producing widely-supported javascript from modern standards and typescript.

Warning

the extractComments option is not supported and all comments will be removed by default, it will be fixed in future

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        minify: TerserPlugin.swcMinify,
        // `terserOptions` options will be passed to `swc` (`@swc/core`)
        // Link to options - https://swc.rs/docs/config-js-minify
        terserOptions: {},
      }),
    ],
  },
};

esbuild

esbuild is an extremely fast JavaScript bundler and minifier.

Warning

the extractComments option is not supported and all legal comments (i.e. copyright, licenses and etc) will be preserved

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        minify: TerserPlugin.esbuildMinify,
        // `terserOptions` options will be passed to `esbuild`
        // Link to options - https://esbuild.github.io/api/#minify
        // Note: the `minify` options is true by default (and override other `minify*` options), so if you want to disable the `minifyIdentifiers` option (or other `minify*` options) please use:
        // terserOptions: {
        //   minify: false,
        //   minifyWhitespace: true,
        //   minifyIdentifiers: false,
        //   minifySyntax: true,
        // },
        terserOptions: {},
      }),
    ],
  },
};

Custom Minify Function

Override default minify function - use uglify-js for minification.

webpack.config.js

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        minify: (file, sourceMap) => {
          // https://github.com/mishoo/UglifyJS2#minify-options
          const uglifyJsOptions = {
            /* your `uglify-js` package options */
          };

          if (sourceMap) {
            uglifyJsOptions.sourceMap = {
              content: sourceMap,
            };
          }

          return require("uglify-js").minify(file, uglifyJsOptions);
        },
      }),
    ],
  },
};

Typescript

With default terser minify function:

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          compress: true,
        },
      }),
    ],
  },
};

With built-in minify functions:

import type { JsMinifyOptions as SwcOptions } from "@swc/core";
import type { MinifyOptions as UglifyJSOptions } from "uglify-js";
import type { TransformOptions as EsbuildOptions } from "esbuild";
import type { MinifyOptions as TerserOptions } from "terser";

module.exports = {
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin<SwcOptions>({
        minify: TerserPlugin.swcMinify,
        terserOptions: {
          // `swc` options
        },
      }),
      new TerserPlugin<UglifyJSOptions>({
        minify: TerserPlugin.uglifyJsMinify,
        terserOptions: {
          // `uglif-js` options
        },
      }),
      new TerserPlugin<EsbuildOptions>({
        minify: TerserPlugin.esbuildMinify,
        terserOptions: {
          // `esbuild` options
        },
      }),

      // Alternative usage:
      new TerserPlugin<TerserOptions>({
        minify: TerserPlugin.terserMinify,
        terserOptions: {
          // `terser` options
        },
      }),
    ],
  },
};

Contributing

Please take a moment to read our contributing guidelines if you haven't yet done so.

CONTRIBUTING

License

MIT

Keywords

FAQs

Last updated on 28 Dec 2023

Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install

Related posts

SocketSocket SOC 2 Logo

Product

  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap

Stay in touch

Get open source security insights delivered straight into your inbox.


  • Terms
  • Privacy
  • Security

Made with โšก๏ธ by Socket Inc