grunt-contrib-cssmin

What is grunt-contrib-cssmin?

The grunt-contrib-cssmin package is a Grunt plugin that helps you minify CSS files. It uses the clean-css library to perform the minification, which reduces the size of CSS files by removing unnecessary whitespace, comments, and other redundant data. This can help improve the performance of your web applications by reducing the amount of data that needs to be transferred over the network.

What are grunt-contrib-cssmin's main functionalities?

Minify CSS files

This feature allows you to minify CSS files. The code sample demonstrates how to configure the grunt-contrib-cssmin plugin to minify all CSS files in the 'src/css' directory and output the minified files to the 'dist/css' directory with a '.min.css' extension.

{
  "grunt.initConfig": {
    "cssmin": {
      "target": {
        "files": [{
          "expand": true,
          "cwd": "src/css",
          "src": ["*.css", "!*.min.css"],
          "dest": "dist/css",
          "ext": ".min.css"
        }]
      }
    }
  },
  "grunt.loadNpmTasks": "grunt-contrib-cssmin",
  "grunt.registerTask": ["default", ["cssmin"]]
}

Combine and minify multiple CSS files

This feature allows you to combine multiple CSS files into a single file and then minify it. The code sample shows how to configure the plugin to combine 'file1.css' and 'file2.css' from the 'src/css' directory into a single 'combined.min.css' file in the 'dist/css' directory.

{
  "grunt.initConfig": {
    "cssmin": {
      "target": {
        "files": {
          "dist/css/combined.min.css": ["src/css/file1.css", "src/css/file2.css"]
        }
      }
    }
  },
  "grunt.loadNpmTasks": "grunt-contrib-cssmin",
  "grunt.registerTask": ["default", ["cssmin"]]
}

Other packages similar to grunt-contrib-cssmin

clean-css

clean-css is a fast and efficient CSS optimizer for Node.js. It is the underlying library used by grunt-contrib-cssmin for minification. While grunt-contrib-cssmin is a Grunt plugin, clean-css can be used directly in Node.js projects without the need for Grunt.

cssnano

cssnano is a modern, modular CSS minifier that is built on top of the PostCSS ecosystem. It offers a wide range of optimizations and is highly configurable. Unlike grunt-contrib-cssmin, which is a Grunt plugin, cssnano can be used with various build tools and task runners, including Gulp and Webpack.

uglifycss

uglifycss is a simple CSS minifier that removes comments and whitespace. It is less feature-rich compared to grunt-contrib-cssmin and clean-css, but it is very fast and can be a good choice for simple minification tasks.

README

grunt-contrib-cssmin

Compress CSS files.

Getting Started

This plugin requires Grunt ~0.4.0

If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:

npm install grunt-contrib-cssmin --save-dev

Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:

grunt.loadNpmTasks('grunt-contrib-cssmin');

This plugin was designed to work with Grunt 0.4.x. If you're still using grunt v0.3.x it's strongly recommended that you upgrade, but in case you can't please use v0.3.2.

Cssmin task

Run this task with the grunt cssmin command.

Task targets, files and options may be specified according to the grunt Configuring tasks guide.

Files are compressed with clean-css.

Options

banner

Type: String Default: null

Prefix the compressed source with the given banner, with a linebreak inbetween.

keepSpecialComments

Type: String Number Default: '*'

To keep or remove special comments, exposing the underlying option from clean-css.. '*' for keeping all (default), 1 for keeping first one, 0 for removing all.

report

Choices: false, 'min', 'gzip' Default: false

Either do not report anything, report only minification result, or report minification and gzip results. This is useful to see exactly how well clean-css is performing but using 'gzip' will make the task take 5-10x longer to complete.

Example ouput using 'gzip':

Original: 198444 bytes.
Minified: 101615 bytes.
Gzipped:  20084 bytes.

Usage Examples

Combine two files into one output file

cssmin: {
  combine: {
    files: {
      'path/to/output.css': ['path/to/input_one.css', 'path/to/input_two.css']
    }
  }
}

Add a banner

cssmin: {
  add_banner: {
    options: {
      banner: '/* My minified css file */'
    },
    files: {
      'path/to/output.css': ['path/to/**/*.css']
    }
  }
}

Minify all contents of a release directory and add a .min.css extension

cssmin: {
  minify: {
    expand: true,
    cwd: 'release/css/',
    src: ['*.css', '!*.min.css'],
    dest: 'release/css/',
    ext: '.min.css'
  }
}

Release History

• 2013-05-25   v0.6.1   Support import in-lining vis clean-css ~1.0.4.
• 2013-04-05   v0.6.0   Update clean-css dependency to ~1.0.0
• 2013-03-14   v0.5.0   Support for 'report' option (false by default)
• 2013-03-10   v0.4.2   Add banner option Support clean-css keepSpecialComments
• 2013-02-17   v0.4.1   Update clean-css dependency to ~0.10.0
• 2013-02-15   v0.4.0   First official release for Grunt 0.4.0.
• 2013-01-23   v0.4.0rc7   Updating grunt/gruntplugin dependencies to rc7. Changing in-development grunt/gruntplugin dependency versions from tilde version ranges to specific versions.
• 2013-01-09   v0.4.0rc5   Updating to work with grunt v0.4.0rc5. Switching to this.files api.
• 2012-11-01   v0.3.2   Update clean-css dep.
• 2012-10-12   v0.3.1   Rename grunt-contrib-lib dep to grunt-lib-contrib.
• 2012-09-23   v0.3.0   Options no longer accepted from global config key.
• 2012-09-10   v0.2.0   Refactored from grunt-contrib into individual repo.

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Task submitted by Tim Branyen

This file was generated on Sat May 25 2013 18:52:13.