Tailwind CSS Class Obfuscation - Overview

Introduction

This monorepo demonstrates different approaches to obfuscating Tailwind CSS classes across various project types and Tailwind versions. Class obfuscation (also known as "class mangling") transforms readable class names like bg-blue-500 into short, opaque names like tw-a, making it harder to reverse-engineer your CSS design system.

Why Obfuscate CSS Classes?

1. Intellectual Property Protection: Hide your design system implementation details
2. Reduced Bundle Size: Shorter class names mean smaller CSS and HTML files
3. Discourage Copying: Makes it harder for competitors to copy your styling

Project Structure

Obfuscation Approaches by Project Type

Project Type	Tailwind	Class Extraction	Obfuscation
HTML Static	v3	tailwindcss-patch	unplugin-tailwindcss-mangle
HTML Static	v4	Custom script	unplugin-tailwindcss-mangle
Next.js	v3	tailwindcss-patch	unplugin-tailwindcss-mangle (webpack)
Next.js	v4	Custom script	unplugin-tailwindcss-mangle (webpack)

Key Differences: Tailwind v3 vs v4

Tailwind v3

• Configuration via tailwind.config.js
• Uses PostCSS plugin
• tailwindcss-patch works for class extraction
• Import: @tailwind base; @tailwind components; @tailwind utilities;

Tailwind v4

• CSS-first configuration with @theme and @import "tailwindcss"
• No tailwind.config.js required
• tailwindcss-patch does NOT work (see the Mangle Tailwind v4 Issues research page)
• Requires custom extraction script
• New features: Container queries (@container), improved arbitrary values

Quick Start

# Install dependencies
pnpm install

# Run all apps in development mode
pnpm dev

# Build all apps (with obfuscation)
pnpm build

# Run tests
pnpm test

Related Pages

• Tailwind v3 — HTML static
• Tailwind v4 — HTML static
• Tailwind v3 — Next.js
• Tailwind v4 — Next.js
• Mangle Tailwind v4 Issues — why tailwindcss-patch doesn't work with v4
• Compatibility — full framework + Tailwind feature matrix

Important Rules

Static Classes Only

For obfuscation to work, classes must be written as complete static strings:

// BAD - Will NOT be obfuscated
<div className={`bg-${color}-500`}>
<div className={"bg-" + color}>

// GOOD - Will be obfuscated
<div className={color === 'red' ? 'bg-red-500' : 'bg-blue-500'}>
<div className="bg-red-500 bg-blue-500">

Build Pipeline

1. Extract Classes: Scan source files for Tailwind classes
2. Generate JSON: Create a class list file
3. Build: Run the normal build process
4. Obfuscate: Replace class names with short versions

Contributing

Each app is independent and can be modified without affecting others. When adding new obfuscation techniques, please update the relevant documentation file.