uncss/grunt-uncss
Grunt Uncss
grunt-uncss is a CSS dead code eliminator and static analysis build tool. It functions as a Grunt CSS optimization plugin that identifies and deletes redundant style rules to reduce stylesheet file sizes and improve frontend performance.
The tool analyzes HTML files and headless browser DOM states to detect styles that do not match any elements in the markup. It supports the protection of specific selectors through whitelists to ensure that styles for dynamically injected elements are preserved during the cleanup process.
The project covers frontend asset minification by compressing cleaned stylesheets into a compact format. It integrates these optimization and minification tasks directly into Grunt build pipelines to maintain lean web assets.
Features
- Dead Code Elimination - Identifies and deletes redundant style rules through static analysis to reduce stylesheet file sizes.
- CSS Unused Style Removers - Identifies and deletes unused CSS selectors by analyzing HTML markup and rendered DOM states.
- CSS AST Analysis - Uses abstract syntax trees to analyze CSS stylesheets and identify redundant style rules for removal.
- HTML Static Analysis - Performs static analysis on HTML markup to identify unique class names and redundant styles.
- Class and Identifier Extraction - Scans source HTML files to identify unique class names and identifiers used as style targets.
- Syntax Tree Analysis - Employs syntax tree analysis to evaluate selector specificity and match rules against active elements.
- Frontend Performance Optimization - Implements automated removal of unused CSS selectors to improve page load speeds and overall frontend performance.
- Headless Rendering Engines - Utilizes a headless rendering engine to evaluate computed styles and determine which CSS selectors are active.
- Web Asset Minifiers - Compresses cleaned stylesheets into a compact format to minimize the total payload delivered to the browser.
- CSS Minification - Reconstructs cleaned CSS rules into a compact format to minimize final file size.
- Static Source Analysis - Parses web project source code without execution to detect and eliminate styles that do not match any elements.
- Build Automation - Integrates CSS optimization and minification tasks directly into a Grunt-based build automation workflow.
- Build Pipeline Integrations - Integrates the CSS cleanup process as a standard step within the project build pipeline.
- Build Tool Integrations - Provides native Grunt task integrations to automate CSS cleaning and minification in build workflows.
- Frontend Asset Compression - Compresses cleaned stylesheets into a compact format to reduce the frontend payload.
- Selector Preservation - Ensures CSS remains functional for dynamically injected content by protecting specific selectors during cleanup.
- CSS Selector Purging - Protects designated CSS selectors from being purged to ensure styles remain for runtime elements.
- Selector Exclusion Strategies - Allows defining a list of styles to ignore during cleanup to protect dynamically injected elements.
- CSS Selector Whitelists - Provides whitelists to protect specific CSS selectors from being removed during the cleanup process.
- Build Automation Pipelines - Provides an automated pipeline for cleaning and optimizing CSS assets as part of the production build process.
- Asset Optimization - Removes unused CSS selectors via Grunt.
