Minify

Minify, in computing, refers to the process of removing all unnecessary characters from source code, markup, or data so that it remains functionally equivalent but requires fewer bytes to transmit or store. The goal is to reduce file size to improve load times, bandwidth usage, and performance in web and software applications. Typical reductions include removing whitespace, comments, unused code, and line breaks, as well as shortening variable names and sometimes reformatting code in safe ways that preserve behavior.

Minification is commonly applied to JavaScript, CSS, HTML, JSON, and SVG files. In JavaScript, minifiers perform whitespace removal, name mangling, dead-code elimination, and other optimizations. In CSS, they collapse whitespace, remove comments, shorten color values, and optimize selectors. In HTML, minification may remove unnecessary spaces and comments while preserving content and structure. Tools may also produce source maps to link minified code back to the original source for debugging.

Minification is typically integrated into build pipelines and asset pipelines using specialized tools. Examples include Terser or UglifyJS for JavaScript, cssnano for CSS, HTMLMinifier for HTML, and various plugins in bundlers like Webpack or Rollup. While minification reduces file size, it is distinct from general data compression (such as gzip or Brotli applied during transfer) and from obfuscation, which aims to conceal code intent rather than merely reduce size. Minified assets should be tested to ensure compatibility, and developers often rely on source maps to aid debugging in production environments.