TwMerge 1.0.1

TailwindMerge 🍃

A high-performance .NET library for merging Tailwind CSS class names with full conflict resolution, deduplication, and support for all major Tailwind v4 utilities, responsive breakpoints, and modifiers.

Features

• Tailwind v4 Support: Handles all major class groups, including text, font, spacing, layout, color, and more
• Conflict Resolution: Automatically removes conflicting or duplicate classes, keeping only the last in each group
• Responsive & Modifier Aware: Correctly merges classes with responsive prefixes (sm:, md:, etc.) and modifiers (hover:, focus:, dark:, etc.)
• Arbitrary Value Support: Handles arbitrary values and custom properties (e.g., w-[32px])
• High Performance: Zero-allocation merging with LRU caching for repeated merges
• Customizable: Extend or override class groups and conflict rules via configuration

Installation

dotnet add package TailwindMerge

Quick Start

1. Add TailwindMerge to your project and create a merger instance:

using TailwindMerge;
 
// Create instance with default config
var twMerge = new TwMerge(); 

2. Merge Tailwind class names:

// merged == "w-4 hover:w-4 text-blue-500"
var merged = twMerge.Merge("w-3", "w-4", "hover:w-3", "hover:w-4", "text-red-500", "text-blue-500"); 

Core Components

TwMerge

The main entry point for merging Tailwind CSS class names, resolving conflicts and removing duplicates.

TwConfig

Configures class groups, conflict rules, theme, and other options. Use TwConfig.Default() for standard Tailwind v4 support, or customize as needed.

Configuration Options

You can customize merging behavior by creating a custom TwConfig:

var config = new TwConfig()
    .CacheSize(1000)
    .ClassGroups(customClassGroups)
    .Separator(":")
    .Prefix("tw-")
    .ConflictingClassGroups(customConflicts);

var twMerge = new TwMerge(config);

Example Usage

var twMerge = new TwMerge();
var result = twMerge.Merge( "sm:text-xs", "sm:text-lg", "md:text-base", "md:text-xl", "p-2", "p-4", "hover:bg-red-500", "hover:bg-blue-500" ); // result == "sm:text-lg md:text-xl p-4 hover:bg-blue-500"

Requirements

• .NET 9.0 or higher

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License.