20 Best JavaScript Minifying Tools

Minifying or code compression is a technique (also called code minimization or code compression) of removing all unnecessary characters from the source code like unwanted white space characters, new line characters, comments, etc. It does not harm the functionality of the source code. It however, improves load time (and your web app’s performance) because the size of the file to be downloaded now reduces.

Here is the list of 20 Best JavaScript Minifying Tools that will help you to optimize, and compress your code to make it more effective and readable.

1. YUI Compressor

YUI Compressor
YUI Compressor is an excellent command-line tool written in Java that allows you to minify your JavaScript files. It is 100% safe and yields a higher compression ratio than most other tools. The YUI Compressor can compress CSS files as well.

2. Google Closure Compiler

closure compiler
The Closure Compiler is a tool for making JavaScript download and run faster. It is a true compiler for JavaScript. Instead of compiling from a source language to machine code, it compiles from JavaScript to better JavaScript. It parses your JavaScript, analyzes it, removes dead code and rewrites and minimizes what's left. It also checks syntax, variable references, and types, and warns about common JavaScript pitfalls.

3. JS Min

JSMin is a filter which removes comments and unnecessary whitespace from JavaScript files. It typically reduces filesize by half, resulting in faster downloads. It also encourages a more expressive programming style because it eliminates the download cost of clean, literate self-documentation.

4. JS Compress

js compress
JSCompress.com is an online javascript compressor that allows you to compress and minify your javascript files. Compressed javascript files are ideal for production environments since they typically reduce the size of the file by 30-90%. Most of the filesize reduction is achieved by removing comments and extra whitespace characters that are not needed by web browsers or visitors.

5. Packer

Packer by Dean Edwards is also a very popular JavaScript compressor, which automatically creates a compressed version of your code. Just paste in the code and hit the ‘Pack’ button.

6. Dojo Shrinksafe

ShrinkSafe is a JavaScript "compression" system. It can typically reduce the size of your scripts by a third or more, depending on your programming style. Many other tools also shrink JavaScript files, but ShrinkSafe is different. Instead of relying on brittle regular expressions, ShrinkSafe is based on Rhino, a JavaScript interpreter. This allows ShrinkSafe to transform the source of a file with much more confidence that the resulting script will function identically to the file you uploaded. Best of all, ShrinkSafe will never change a public variable or API. That means that you can drop the compressed version of your JavaScript into your pages without changing the code that uses it.

7. Smaller

Smaller is handy JavaScript minifying tool that has the ability to combine several files into one. Compress your files and make your websites load faster. It works for HTML, CSS and JavaScript Compress for OSX.

8. Ultra Minifier

Ultra Minifier is the simplest YUI Compressor GUI to minify Javascript and CSS code without using the Terminal.

9. AjaxminUI

Microsoft Ajax Minifier   Home
The Microsoft Ajax Minifier enables you to improve the performance of your web applications by reducing the size of your Cascading Style Sheet and JavaScript files. Use the -analyze option on the command-line to provide lint-style syntax checking and variable analysis of your code.

10. Ajax Minifier

This tool is a Windows application that allows you to run the Microsoft Ajax Minifier without using the command line or Visual Studio. It minifies all javascript files in a folder and nested folders, minify individual javascript files, enable/disable the minifier’s hypercrunch and analysis options and many more.

11. Uglifyjs

This package implements a general-purpose JavaScript parser/compressor/beautifier toolkit. It is developed on NodeJS, but it should work on any JavaScript platform supporting the CommonJS module system (and if your platform of choice doesn’t support CommonJS, you can easily implement it, or discard the exports.* lines from UglifyJS sources).

12. JavaScript Optimizer

javascript optimizer
This tool will let you optimize your JavaScript (JScript) code by removing comments, whitespace as well as other unnecessary characters as well as by optionally shortening function / variable / class names. Other than regular JavaScript code, this tool accepts extensions (based on C/C++ preprocessor syntax) which allow further optimization, in particular shortening custom names (e.g. of functions, variables, classes) and conditionally removing unused portions of code (e.g. used for debugging purposes or versions for different browsers).

13. JavaScript Minifier

It is a handy tool with an API to minify your JavaScript code with less efforts.

14. JavaSript Minify

Minifying Javascript takes the pretty well formed JS code that you have written and removes the spacing, indentation, newlines, and comments. These are not required for Javascript to run successfully. It also makes the Javascript more difficult to read when viewing the source.

15. Minifier

A simple tool for minifying CSS/JS without a big setup. It reworks URLs in CSS from the original location to the output location. It automatically resolves @import statements in CSS.

16. Gulp

Gulp.js is the streaming build system. It’s use of streams and code-over-configuration makes for a simpler and more intuitive build. By preferring code over configuration, gulp keeps simple things simple and makes complex tasks manageable.

17. Grunt

Grunt is a task-based command line build tool for JavaScript projects. It has the following predefined tasks that you can use in your project: Concatenate files, Validate files with JSHint, Minify files with UglifyJS, Run unit tests with node unit and etc.

18. Koala

Koala is a GUI application for Less, Sass, Compass and CoffeeScript compilation, to help web developers to use them more efficiently. Koala can run in windows, linux and mac.

19. Prepros

Prepros is a tool to compile LESS, Sass, Compass, Stylus, Jade and much more with automatic CSS prefixing, It comes with built in server for cross browser testing. It runs on windows, mac and linux.

20. Online JavaScript/CSS Compressor

This is a web interface to compress your JavaScript or CSS. This tool uses UglifyJS 2, Clean-CSS and HTML Minifier.