---
name: thedaviddias/unused-css
source: https://app.decimal.ai/s/thedaviddias-unused-css@1/SKILL.md
source_sha256: 65c57d7e649d
---

# Remove unused CSS rules

Most projects use only 10-25% of their CSS—removing the rest can cut bundle sizes by 75%+ and dramatically improve load times.

## Quick Reference

- Use PurgeCSS or UnCSS to remove unused selectors
- Integrate into build pipeline (Webpack, Vite, PostCSS)
- Safelist dynamic classes and framework-specific patterns
- Typical reduction: 50-90% for CSS framework users

## Check

Use tools like PurgeCSS, UnCSS, or Chrome DevTools Coverage to identify and remove unused CSS to reduce bundle size and improve performance.

## Fix

Implement automated unused CSS removal in your build process and regularly audit CSS files to eliminate dead code and unused selectors.

## Explain

Explain how unused CSS bloats bundle sizes, slows page loading, and how modern tools can safely remove unused styles without breaking functionality.

## Code Review

Review stylesheets, component styles, and responsive states related to Remove unused CSS rules. Flag exact selectors, declarations, or breakpoints that violate the rule in the rendered UI.

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For full implementation details, code examples, and framework-specific guidance,
see `references/rule.md`.

Rule page: https://frontendchecklist.io/en/rules/css/unused-css