ClosureCompiler.js: Closure Compiler for node.js. The all-round carefree package.

npm install closurecompiler
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ClosureCompiler.js - Closure Compiler for node.js

The all-round carefree package. Automatically downloads and sets up Closure Compiler and a JRE built from OpenJDK if required. No environment variables to set, works out of the box.

-- „Stop uglifying, be a man!“


Install: npm -g install closurecompiler

Installing globally is recommended if no global JRE is available and the bundled JRE needs to be downloaded, which is about 45mb large.

ClosureCompiler API

The API is quite simple and fully explained in a few lines of code:

var ClosureCompiler = require("closurecompiler");

    ['file1.js', 'file2.js'],
        // Options in the API exclude the "--" prefix
        compilation_level: "ADVANCED_OPTIMIZATIONS",

        // Capitalization does not matter 
        Formatting: "PRETTY_PRINT",

        // If you specify a directory here, all files inside are used
        externs: ["externs/file3.js", "externs/contrib/"],

        // ^ As you've seen, multiple options with the same name are
        //   specified using an array.
    function(error, result) {
        if (result) {
            // Write result to file
            // Display error (warnings from stderr)
        } else {
            // Display error...

Command line utility

Usage:   ccjs sourceFiles ... [--option=value --flagOption ...] [> outFile]

Available options

The API and ccjs support all the command line options of Closure Compiler except --js and --js_output_file.

Usage with Grunt

To simply include ClosureCompiler.js as a Grunt task, see: grunt-closurecompiler


-- „Be a hero!“

Externs for node.js

ClosureCompiler.js depends on the closurecompiler-externs package, an npm distribution of node.js Closure Compiler Externs, which includes externs for all of node's core modules. As a result, specifiying --externs=node automatically includes all node.js specific externs in your compile step. If you are using non-core modules, you may still need additional externs for these.


To update ClosureCompiler.js and/or the underlying Closure Compiler package, just run npm update. This will automatically download and set up the latest version of Closure Compiler to be used by ClosureCompiler.js.

Using custom Closure Compiler builds

If you want to use a custom Closure Compiler build for whatever reason, just replace the files in the compiler/ directory.


Tests Build Status


Feross Aboukhadijeh


ClosureCompiler.js and Closure Compiler itself

Apache License, Version 2.0 -


MPL 2.0 License -

Bundled JRE

Binary License for OpenJDK -

This package is not officially supported by Google, Mozilla or Oracle. All rights belong to their respective owners.

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