clean-css/clean-css
Clean Css
Clean-CSS is a Node.js CSS optimizer that functions as a minifier, bundler, and post-processor. It is designed to decrease total stylesheet volume by removing whitespace, comments, and redundant code.
The project provides a pipeline for applying custom transformations and browser compatibility adjustments. It allows for the programmatic modification of CSS rules and values through a plugin system and the use of custom optimization plugins.
The tool covers a broad range of asset optimization capabilities, including stylesheet bundling, import rule inlining, and relative URL rebasing. It also supports source map generation for debugging and customizable output formatting for beautification.
Features
- CSS Minification - Compresses stylesheets by removing whitespace, comments, and redundant code to reduce total file size.
- Stylesheet Bundling - Concatenates multiple CSS files or strings into a single optimized output bundle while maintaining order.
- CSS Processors - Implements a processing pipeline for applying custom transformations and browser compatibility adjustments to stylesheets.
- CSS Transformation Plugins - Implements a plugin system specifically designed to modify the CSS abstract syntax tree during optimization.
- Abstract Syntax Tree Parsing - Parses stylesheets into a structured tree representation to enable programmatic rule merging and selector simplification.
- CSS Selector Minification - Simplifies complex selectors and rules to reduce the total byte count of the output.
- CSS Bundlers - Aggregates multiple stylesheets into a single output file and resolves inline import rules.
- CSS Minifiers - Minifies CSS files by removing unnecessary characters, whitespace, and merging redundant rules.
- CSS Optimizers - Provides a JavaScript-based engine to optimize CSS properties and selectors to minimize overall stylesheet size.
- CSS Property Minification - Reduces size by merging adjacent rules and shortening color representations.
- Frontend Asset Optimization - Optimizes frontend assets by compressing CSS and refining properties to decrease the total byte count sent to browsers.
- CSS AST Transformations - Programmatically modifies CSS structures and values using tree traversal and plugins for custom requirements.
- Remote Dependency Inliners - Fetches and merges external CSS import rules from remote sources directly into the local stylesheet during build.
- CSS Source Mapping - Generates source maps that link minified CSS production files back to their original source code for debugging.
- Source Map Generation - Generates mapping files between original source CSS and the optimized output for debugging.
- CSS Rule Preservation Markers - Uses specialized preservation comments to prevent the removal of specific style rules during optimization.
- Browser Compatibility Targets - Adjusts output behavior based on defined minimum browser versions to ensure compatibility with legacy environments.
- CSS Value Optimizers - Shortens color and gradient parameters into their smallest possible valid representations using optimization plugins.
- CSS Optimization Levels - Provides selectable optimization levels to control the aggressiveness of CSS code reduction.
- CSS Pipeline Extensions - Enables the definition of custom logic within the minification pipeline to modify CSS rules.
- URL Relative Path Resolvers - Recalculates relative asset paths dynamically to ensure images and fonts remain linked when stylesheets are moved.
- CSS Import Inlining - Resolves and merges CSS import statements from local or remote sources directly into the stylesheet.
- Asset Optimization - Fast and efficient CSS minification for Node.js.
- Code Minifiers - CSS file minification and optimization.
