outstripped UglifyJS when measured in daily downloads. Source mapping A Source Map is a file format that allows software tools for JavaScript to display different code to a user than the code actually executed by the computer. For example, to aid in debugging of minified code, by "mapping" this code to the original unminified source code instead. The original format was created by Joseph Schorr as part of the Closure Inspector minification project. Version 2 and 3 of the format reduced the size of the map files considerably. Types Tools Visual Studio Code comes with minification support for several languages. It can readily browse the Visual Studio Marketplace to download and install additional minifiers. JavaScript optimizers which can minify and generate source maps include UglifyJS and Google Closure Compiler. In addition, certain online tools, such as Microsoft Ajax Minifier, the Yahoo! YUI Compressor or Pretty Diff, can compress CSS files. For minification of HTML code there are the following tools: HtmlCompressor, HTMLMinifier and WebMarkupMin. There is a Power-Shell script named "minifyPS" that is able to shrink PowerShell script code as well as JavaScript code. Web development Components and libraries for Web applications and websites have been developed to optimize file requests and reduce page load times by shrinking the size of various files. JavaScript and Cascading Style Sheet (CSS) resources may be minified, preserving their behavior while considerably reducing their file size. Libraries available online are capable of minification and optimization to varying degrees. Some libraries also merge multiple script files into a single file for client download. JavaScript source maps can make code readable and debuggable even after it has been combined and minified. References Source code JavaScript