Use build blocks to update the references in your html and perform file concatenation, minification, and cache busting.

npm install grunt-useref
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| Current version is Grunt 0.4.0 compatible.  |
| Version 0.0.12+ is Grunt 0.4.0 compatible.  |
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| Version 0.0.11 is Grunt 0.3.17 compatible.  |
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Use build blocks to do three things:

  1. update the references in your html from orginals to an optionally versioned, optimized file
  2. perform file concatenation
  3. Perform file minification.

Utilize build blocks in your html to indicate the files to be concatenated and minified. This task will parse the build blocks by updating the <script> and <style> blocks in your html, and it will schedule the concatenation and minification of the desired files by dynamically updating the concat, uglify, and cssmin (part of grunt-css - this is auto included as a dependency for grunt-useref) tasks.

This task modifies files, so it should be executed on a temp directory or the final build directory.

This task relies on the concat, uglify, and cssmin tasks to be run after it... concat first.

Inspiration (and large chunks of code) for grunt-useref was taken from the usemin tasks of H5BP and Yeoman.


Here is a sample repo that uses grunt-useref.

To look at a working example see the grunt.js of this module and look at test/input of this module.

Example usage with grunt.init:

in grunt.js:

    useref: {
        // specify which files contain the build blocks
        html: 'output/**/*.html',
        // explicitly specify the temp directory you are working in
        // this is the the base of your links ( "/" )
        temp: 'output'

Below are example corresponding build blocks in an example referenced html file. Multiple build blocks may be used in a single file. The grunt templating engine can be used in the build file descriptions. The data passed to the template processing is the entire config object.

in an html file within the output directory

<!-- build:css /css/combined.css -->
<link href="/css/one.css" rel="stylesheet">
<link href="/css/two.css" rel="stylesheet">
<!-- endbuild -->

<!-- build:js scripts/combined.<%= grunt.file.readJSON('package.json').version %>.concat.min.js -->
<!-- You can put comments in here too -->
<script type="text/javascript" src="scripts/this.js"></script>
<script type="text/javascript" src="scripts/that.js"></script>
<!-- endbuild -->

<!-- build:js scripts/script1.<%='yyyy-mm-dd') %>.min.js -->
<script type="text/javascript" src="scripts/script1.js"></script>
<!-- endbuild -->

The example above has three build blocks on the same page. The first two blocks concat and minify. The third block minifies one file. They all put the new scripts into a newly named file. The original JavaScript files remain untouched in this case due to the naming of the output files.

You can put comments and empty lines within build blocks.

Assuming your package.json.version is 0.1.0 after the bump, and it is October 31, 2012 running grunt useref would create the following three files:

# concat and minified one.css + two.css

# concat and minified this.js + that.js

# minified script1.js

Also the html in the file with the build blocks would be updated to:

<link href="/css/combined.css" rel="stylesheet">

<script type="text/javascript" src="scripts/combined.0.1.0.concat.min.js"></script>

<script type="text/javascript" src="scripts/script1.2012-10-31.min.js"></script>

Finally, make sure to schedule concat, uglify and cssmin in your grunt.js. You must schedule these after useref. You do not need to create grunt.init entries for them. If the build blocks do not create work for any one of these tasks, you can leave that one out.

For example:

grunt.registerTask('build', ['cp', 'useref', 'concat', 'uglify', 'cssmin');

Or, if you are do not have any css build blocks:

grunt.registerTask('build', ['cp', 'useref', 'concat', 'uglify');

Installation and Use

To use this package put it as a dependency in your package.json, and then run npm install.

Then load the grunt task in your grunt.js


If you use grunt-useref you can ommit using loadNpmTask for the following plugins:


grunt-useref will load the above plugins for you.


Currently there are no autmated tests, but the test directory does have a working sample setup. To try out the sample run it from the grunt-useref directory using:

npm install
npm test

You can inspect the sample output created. The tests can be run by either cloning the git repo or from this module's directory inside the node_modules folder of your project.

Change Log

  • 0.0.16 - Mar 01, 2013 - Allow empty lines and comments within build blocks for Grunt0.4.0
  • 0.0.15 - Feb 23, 2013 - Adding grunt 0.4.0 compatibility
  • 0.0.11 - Jan 03, 2013 - Making grunt log output a little less obnoxious.
  • 0.0.10 - Jan 02, 2013 - Allow empty lines and comments within build blocks
  • 0.0.9 - Dec 23, 2012 - Setting grunt-css dependency to 0.3.2, since 0.4.1 breaks useref - plan to update when grunt goes to 0.4
  • 0.0.7 - Nov 27, 2012 - fixed the css minification task so it does not have to be included in your grunt.js as a dependency
  • 0.0.6 - Nov 26, 2012 - updated css minification task and its dependency

NPM module

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