A grunt plugin to minified given files with grunt
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Latest commit ba9a389 Mar 16, 2013 @phun-ky Fixed typo



A grunt plugin to minify given JavaScript files

No more development

This plugin was originally intended to add some features grunt-contrib-uglify did not supply under Grunt 0.3. After the Grunt 0.4 release, there's no longer need for grunt-minified.

I will no longer develop this plugin any further and I strongly suggest users of this plugin to either fork it and continue the development on their hand, or use the fully featured grunt-contrib-uglify plugin.

Getting Started

Install this grunt plugin next to your project's Gruntfile.js with:

npm install grunt-minified

Then add this line to your project's Gruntfile.js:



Add something like this in your gruntfile:

minified : {
  files: {
    src: [
    dest: '/js/min/'
  options : {
    sourcemap: true,
    allinone: false

With this configuration, grunt-minified will output a minified file and a sourcemap per parsed file with this filename structure: <filename>.min.js in the dest folder.


Grunt-minified currently supports these options:


  • Type: Boolean
  • Defaults: false

Generate a sourcemap for the generated files(s) if toggled. The output files is saved with this filename structure: <filename>.js.map in the dest folder.


  • Type: Boolean
  • Defaults: false

Generate just one minified file if toggled. Output file is saved as minified.js if options.dest_filename is not set.


  • Type: String
  • Defaults: minified.js

If allinone is set, grunt-minified will use dest_filename for the generated sourcemap. No point of setting this if allinone is set to false. Currently, this is a copy & paste from UgliyJS2, YMMV.


  • Type: String
  • Defaults: null

If ext is set, grunt-minified will replace the files current extention with ext. The extension must begin with a . to work correctly. Eg .min.js. This will also override the extension of dest_filename if set.


  • Type: Object
  • Defaults: null

If mirrorSource.path is set, grunt-minified will mirror the destination path to the source path of each file that is processed. You must supply at path property for mirrorSource to work.

  • Type: 'String'
  • Defaults: null

mirrorSource.path is a String that describes the base path of the source folder that you would like to mirror. The mirrorSource.path will be replaced by files.dest.

Example configuration using mirrorSource:

minified : {
  dev: {
    files: {
      src: [
      dest: 'deploy'
    options : {
      sourcemap: false,
      allinone: false,
      mirrorSource: {
        path: 'source/js/'
      ext: '.min.js'

Example folder output using mirrorSource:

├─┬ source
| ├─┬ folder_a
|   ├── a.js
|   └─┬ folder_ab
|     └── ab.js
├─┬ deploy
| ├─┬ folder_a
|   ├── a.min.js
|   └─┬ folder_ab
|     └── ab.min.js


  • Type: Object
  • Defaults: {}

If uglifyOpts is set, grunt-minified will pass along the options to uglify-js. Below is a list of options that are available:

  • warnings: (default false) - pass true to display compressor warnings.
  • fromString: (default false) - if you pass true then you can pass JavaScript source code, rather than file names.
  • mangle: pass false to skip mangling names.
  • output: (default null) - pass an object if you wish to specify additional Beautifier options. The defaults are optimized for best compressions. Please see UglifyJS - the code generator for more details.
  • compress: (default {}) - pass false to skip compressing entirely. Pass an object to specify custom compressor options. Please see UglifyJS - the compressor for more details.
Beautifier options
  • beautify (default true) -- whether to actually beautify the output.
  • indent-level (default 4)
  • indent-start (default 0) -- prefix all lines by that many spaces
  • quote-keys (default false) -- pass true to quote all keys in literal objects
  • space-colon (default true) -- insert a space after the colon signs
  • ascii-only (default false) -- escape Unicode characters in strings and regexps
  • inline-script (default false) -- escape the slash in occurrences of </script in strings
  • width (default 80) -- only takes effect when beautification is on, this specifies an (orientative) line width that the beautifier will try to obey. It refers to the width of the line text (excluding indentation). It doesn't work very well currently, but it does make the code generated by UglifyJS more readable.
  • max-line-len (default 32000) -- maximum line length (for uglified code)
  • ie-proof (default true) -- generate “IE-proof” code (for now this means add brackets around the do/while in code like this: if (foo) do something(); while (bar); else ....
  • bracketize (default false) -- always insert brackets in if, for, do, while or with statements, even if their body is a single statement.
  • semicolons (default true) -- separate statements with semicolons. If you pass false then whenever possible we will use a newline instead of a semicolon, leading to more readable output of uglified code (size before gzip could be smaller; size after gzip insignificantly larger).
Compressor options

You need to pass --compress (-c) to enable the compressor. Optionally you can pass a comma-separated list of options. Options are in the form foo=bar, or just foo (the latter implies a boolean option that you want to set true; it's effectively a shortcut for foo=true).

The defaults should be tuned for maximum compression on most code. Here are the available options (all are true by default, except hoist_vars):

  • sequences -- join consecutive simple statements using the comma operator

  • properties -- rewrite property access using the dot notation, for example foo["bar"] → foo.bar

  • dead-code -- remove unreachable code

  • drop-debugger -- remove debugger; statements

  • unsafe -- apply "unsafe" transformations (discussion below)

  • conditionals -- apply optimizations for if-s and conditional expressions

  • comparisons -- apply certain optimizations to binary nodes, for example: !(a <= b) → a > b (only when unsafe), attempts to negate binary nodes, e.g. a = !b && !c && !d && !e → a=!(b||c||d||e) etc.

  • evaluate -- attempt to evaluate constant expressions

  • booleans -- various optimizations for boolean context, for example !!a ? b : c → a ? b : c

  • loops -- optimizations for do, while and for loops when we can statically determine the condition

  • unused -- drop unreferenced functions and variables

  • hoist-funs -- hoist function declarations

  • hoist-vars -- hoist var declarations (this is false by default because it seems to increase the size of the output in general)

  • if-return -- optimizations for if/return and if/continue

  • join-vars -- join consecutive var statements

  • cascade -- small optimization for sequences, transform x, x into x and x = something(), x into x = something()

  • warnings -- display warnings when dropping unreachable code or unused declarations etc.

    For more information on UglifyJS, please see the UglifyJS Website


In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using grunt.


Release History

(Until v1.0.0, this will only be updated when major or breaking changes are made)

  • 2013/01/13 - v0.0.5 - Added support for mirroring source to dest and the ability to set a custom file extension on minified files.
  • 2013/01/11 - v0.0.4 - Added support for UglifyJS options
  • 2013/01/10 - v0.0.3 - Added support for grunt v 0.4.0rc5


Copyright (c) 2012 Alexander Vassbotn Røyne-Helgesen Licensed under the GPL license.