UglifyJS 3

UglifyJS is a JavaScript compressor/minifier written in JavaScript. It also contains tools that allow one to automate working with JavaScript code. A parser which produces an abstract syntax tree (AST) from JavaScript code. A code generator which outputs JavaScript code from an AST, also providing the option to get a source map. A compressor (optimizer). it uses the transformer API to optimize an AST into a smaller one. A mangler, reduce names of local variables to (usually) single-letters. A scope analyzer, which is a tool that augments the AST with information about where variables are defined/referenced etc. A tree walker, a simple API allowing you to do something on every node in the AST. A tree transformer, another API intended to transform the tree. All the above utilities and APIs are defined in ~6500 lines of code (except for the effective generation of the source-map, which is handled by the source-map module). Compared to alternatives, UglifyJS is pretty small.