What is shadcn/ui? Understanding Its Purpose, Benefits, and How to Use It in Modern React Apps

Modern React projects often face a tough balance: should you use a prebuilt UI library (fast but inflexible) or design your own system (flexible but slow to build)?
That’s where shadcn/ui comes in, a new approach to UI development that gives you full control over your code while offering the polish of a mature component library.

In this guide, we’ll explore what shadcn/ui is, why it’s become so popular among React and Next.js developers, and how you can use it to speed up your own UI work without losing flexibility.

What Is shadcn/ui?

shadcn/ui (often written simply as shadcn) is not a traditional npm package or a themeable component library like Material UI or Chakra UI.
Instead, it’s a collection of high-quality, open-source React components built with:

• Tailwind CSS (for styling)
• Radix UI (for accessible, unstyled primitives)
• Lucide Icons (for clean, consistent SVG icons)

But here’s the twist:

Instead of installing it as a dependency, you copy the actual source code of each component into your own project.

That means every button, dialog, or dropdown lives in your own codebase, editable, themeable, and version-controlled by you.

You can think of it as a component generator or UI starter kit, not a dependency.

How It Works

The shadcn/ui project provides a CLI tool that scaffolds components directly into your project:

npx shadcn-ui@latest add button

This command downloads a prebuilt, accessible Button component and adds it under your local components/ui/ folder. From there, you can customize it, change Tailwind classes, tweak variants, or adapt it to your design system.

Every component is just React + Tailwind + Radix, no hidden logic or runtime dependency.

Why Developers Use shadcn/ui

1. Full Ownership of Code

Unlike UI libraries where you rely on opaque dependencies, shadcn gives you the full component source. You can:

• Edit styles directly
• Add props or variants
• Integrate custom logic (like analytics or permissions)

It’s your UI, your rules, no waiting for maintainers to merge a PR.

2. Built on Proven Foundations

Each component is built using:

• Tailwind CSS → utility-first styling
• Radix UI → accessible and unstyled base primitives
• Lucide Icons → modern SVG icons
• clsx / tailwind-variants → clean conditional class management

This ensures your components are both accessible and production-ready, following design system best practices out of the box.

3. Consistency and Speed

You get a cohesive, beautiful starting point for your UI:

• Consistent spacing, typography, and color system
• Dark mode and theming via CSS variables
• Ready-to-use layout and interactive patterns (dropdowns, modals, tooltips)

You can start shipping UIs that feel designed, without reinventing every component.

4. No Vendor Lock-In

Because the components are just code, you can:

• Fork them
• Replace them
• Mix with other libraries

If shadcn/ui ever changes or you outgrow it, your components still belong entirely to you.

Common Components and Examples

Here are some of the most popular shadcn/ui components and what they look like in action.

Example 1: Button

import { Button } from '@/components/ui/button'

export default function Example() {
  return (
    <div className="space-x-2">
      <Button>Default</Button>
      <Button variant="outline">Outline</Button>
      <Button variant="destructive">Delete</Button>
    </div>
  )
}

Why it’s great:

• Built-in variants like outline, destructive, and ghost.
• Fully themeable with Tailwind’s design tokens.
• Simple enough to customize without losing consistency.

Understanding the Button Variants

When you run:

npx shadcn-ui@latest add button

The CLI creates a button.tsx file inside components/ui/, typically like this:

// components/ui/button.tsx
import * as React from 'react'
import { cva } from 'class-variance-authority'
import { cn } from '@/lib/utils'

const buttonVariants = cva(
  'inline-flex items-center justify-center rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:opacity-50 disabled:pointer-events-none',
  {
    variants: {
      variant: {
        default: 'bg-primary text-primary-foreground hover:bg-primary/90',
        outline: 'border border-input bg-background hover:bg-accent hover:text-accent-foreground',
        destructive: 'bg-destructive text-destructive-foreground hover:bg-destructive/90',
        ghost: 'hover:bg-accent hover:text-accent-foreground',
        link: 'text-primary underline-offset-4 hover:underline',
      },
      size: {
        default: 'h-10 px-4 py-2',
        sm: 'h-9 rounded-md px-3',
        lg: 'h-11 rounded-md px-8',
        icon: 'h-10 w-10',
      },
    },
    defaultVariants: {
      variant: 'default',
      size: 'default',
    },
  }
)

export interface ButtonProps
  extends React.ButtonHTMLAttributes<HTMLButtonElement>,
    VariantProps<typeof buttonVariants> {}

function Button({ className, variant, size, ...props }: ButtonProps) {
  return <button className={cn(buttonVariants({ variant, size, className }))} {...props} />
}

export { Button, buttonVariants }

So What Are outline, destructive, and ghost?

They’re style variants pre-defined in that buttonVariants configuration. You don’t need to define them manually, they come with the generated component by default.

Each variant maps to a different Tailwind class pattern:

So, when you write:

<Button variant="destructive">Delete</Button>

you’re telling the Button component to use the red danger style, because the variant maps to bg-destructive and text-destructive-foreground.

What Are “Tailwind Design Tokens”?

“Design tokens” are named color and spacing variables used throughout your theme. In shadcn/ui, these are defined in your globals.css (or tailwind.config.js) like so:

:root {
  --background: 0 0% 100%;
  --foreground: 222.2 47.4% 11.2%;
  --primary: 222.2 47.4% 11.2%;
  --primary-foreground: 210 40% 98%;
  --destructive: 0 84.2% 60.2%;
  --destructive-foreground: 210 40% 98%;
  /* etc. */
}

Then Tailwind references them as “tokens” using its theme() syntax or class shortcuts:

className = 'bg-primary text-primary-foreground hover:bg-primary/90'

These tokens:

• Keep colors consistent across components.
• Support dark mode automatically via CSS variables.
• Let designers and developers share one visual language (e.g., “primary”, “accent”, “destructive”) instead of raw hex codes.

Why This Is Useful

• You can add or modify variants (e.g., success, warning) easily in the same button.tsx.
• Your UI stays visually consistent since all variants pull from shared design tokens.
• Updating your theme (colors, spacing, etc.) instantly updates all components.
• It’s flexible, use the built-in variants or extend them to match your brand.

In short: Those variants (outline, destructive, ghost, etc.) are prebuilt, design-token-powered styles you can extend or override. They’re part of what makes shadcn/ui components production-ready out of the box, consistent, theme-aware, and easily customizable.

Example 2: Dialog (Modal)

import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from '@/components/ui/dialog'

export default function Example() {
  return (
    <Dialog>
      <DialogTrigger asChild>
        <Button>Open Dialog</Button>
      </DialogTrigger>
      <DialogContent>
        <DialogHeader>
          <DialogTitle>Confirm Action</DialogTitle>
        </DialogHeader>
        <p>This action cannot be undone.</p>
      </DialogContent>
    </Dialog>
  )
}

Why it’s great: The dialog uses Radix primitives under the hood, meaning it’s keyboard-accessible, screen-reader-friendly, and responsive out of the box.

Example 3: Input and Form Components

import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'

export default function LoginForm() {
  return (
    <form className="space-y-4">
      <div>
        <Label htmlFor="email">Email</Label>
        <Input id="email" type="email" placeholder="you@example.com" />
      </div>
      <Button type="submit">Login</Button>
    </form>
  )
}

Clean, minimal, and easy to extend for any authentication or settings page.

When (and When Not) to Use shadcn/ui

✅ Use It When

• You’re building a custom product (SaaS, dashboard, app) and want consistent UI fast.
• You need full control over design and accessibility.
• You’re already using Tailwind CSS and Next.js.

❌ Avoid It When

• You prefer a drop-in design system (like MUI, Chakra UI).
• You don’t use Tailwind (it’s tightly coupled).
• You want to move extremely fast without touching component code.

Getting Started (Quick Setup)

1. Install Tailwind CSS (if not already):

   npx create-next-app my-app
   cd my-app
   npx tailwindcss init -p
   

2. Initialize shadcn/ui

   npx shadcn-ui@latest init
   

3. Add components

   npx shadcn-ui@latest add button card dialog input
   

4. Import and customize Your new components will appear in components/ui/.

🧩 shadcn vs Other UI Libraries

Key Takeaways

• shadcn/ui isn’t a package, it’s a copy-and-own component model.
• You get real control, no lock-in, and great developer experience.
• Built with Tailwind, Radix, and modern React patterns, it’s ideal for teams who want a clean, accessible, and extendable design foundation.

It’s the perfect middle ground between “build everything yourself” and “depend on a heavy UI library.”