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    minifyjs — A node minifier Build Status

    minifyjs is a Javascript code minifier written for node. It's aim is flexibility.


    minifyjs is an npm package. You should be able to install it using

    npm install minifyjs

    To install the minifyjs command, use

    npm install -g minifyjs

    This will install the current stable version. To install the latest development version, clone this repository and install it.

    git clone git://
    cd minifyjs
    npm install -g

    Congratulations! You're half way to the minified files of your dreams.


    You can use minifyjs from the command line.

    minifyjs [arguments] [-b/m] [-i path/input.js] [-o path/output.js]

    Possible arguments

    • -b or --beautify — Beautify code. The opposite of minifying code.
    • -m or --minify — Minify code. Available options for the minification engine
    • -e or --engine E — Specify an engine. If left unspecified, it defaults to 'best', for minification, or 'js-beautify' for beautification. For a list of available engines, see Engine section below.
    • -l I or --level I — Specify a minification level (does not apply to beautification). Generally, there are three levels available:
      • 0 — Strips whitespace, leaves code intact (depending on engine)
      • 1 — Simple optimizations. Changes code slightly without deep optimization. Probably what you'll want for most code.
      • 2 — Advanced optimizations.
    • -o or --output — Write data to a specific file instead of outputting to STDOUT.

    The concept here is for use within larger projects. You can easily integrate this into your workflow using:

    minifyjs -m mycode.js > mycode.min.js

    This will create a file called mycode.min.js containing the smallest minified version available (see best engine explanation below).

    Or, with a specific engine:

    minifyjs -m -e uglify mycode.js

    Or, beautify with a specific engine:

    minifyjs -b -e js-beautify mycode.js


    Minification engines

    Currently, minifyjs only supports two engines for minification:

    • uglify — Mihai Bazon's amazing UglifyJS2.
    • gccGoogle Closure Compiler via Tim Smart's node-closure. See their API Reference for details.
    • yui — YUI Compressor. This is currently done through Tim Smart's node-yui-compressor module. Currently, minification levels are ignored.
    • best — Custom engine which calls all other engines and compares their output. It finds the smallest (most minified) code, and returns it.

    Beautification engines


    If you'd like to use minifyjs programmatically, you can do so by using require('minifyjs'). Currently, the API looks like this:

    mjs = require('minifyjs');
    //Minify some code
    mjs.minify(code, options, callback);
    //Beautify some code
    mjs.beautify(code, options, callback);


    • code is a stream.Readable containing the code to be processed.
    • options is a key/value hash. Options include: engine (the engine to use), level (Level of minification. The lower, the less minified).
    • callback is a Function to be called once the code is returned from the engine. It's passed back in the format callback(error, code);

    Node that a callback is required because some methods (read: gcc) require asynchronous calls. In order to support this sort of engine, all code comes from callbacks. A good example may be:

    var myCode = "...codehere...";
    function presentCode(error, code) {
        if (error) {
            throw error;
        //Present the code to the user...
    require('minifyjs').minify(myCode, { engine: 'yui' }, presentCode);


    Enjoy! Please fork, push and file issues as desired. Feel free to contribute!




    npm i minifyjs

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