Modern CSS in React: Styled Components, CSS Modules, or Tailwind?

📘 Introduction

When building React apps, choosing how to style your components is a key decision. Some methods work best for large teams, others for fast prototyping. Your decision affects developer speed, scalability, and code readability.

In this article, we’ll compare four popular styling methods:

• Styled Components

• CSS Modules

• Tailwind CSS

• BEM (Block Element Modifier)

We’ll explore how each one works, their pros and cons, and when to use them.

🎨 Styled Components

Styled Components is a popular CSS-in-JS solution that allows you to write actual CSS inside your JavaScript. It uses template literals and attaches styles directly to the component using the styled function.

Example:

Pros:

• Styles are scoped to the component, so you never worry about conflicts

• Dynamic styling with JavaScript variables and props

• Works great with React's component-driven structure

• Supports themes and context-based styling out of the box

Cons:

• Runtime styling adds a small performance cost

• Might confuse beginners by mixing logic and styles

• Larger codebase might see bundle size growth if not optimized

Use it when: You want dynamic styling, scoped CSS, and need to support theming or complex UI behavior in your components.

🧩 CSS Modules

CSS Modules let you write normal .css (or .scss) files but apply styles locally to components. The class names are automatically scoped with unique hashes to prevent conflicts.

Example:

Pros:

• Keeps CSS separate and clean

• Automatically scopes class names to avoid global conflicts

• Easy to use with tools like Webpack, CRA, or Vite

• Works well with pre-processors like Sass

Cons:

• No support for styling based on props without extra logic

• Managing many small CSS files may feel fragmented

• Sharing styles between components can get repetitive

Use it when: You like classic CSS syntax but want safe, maintainable styles in component-based apps. Best for small to medium projects or teams used to traditional CSS.

🌬️ Tailwind CSS

Tailwind is a utility-first CSS framework. Instead of writing custom CSS, you use utility classes like bg-blue-500, text-sm, or flex directly in your JSX.

Example:

Pros:

• Build UIs quickly with predefined styles

• Extremely small final bundle size with tree-shaking

• Highly customizable with a config file

• Encourages design consistency across the app

Cons:

• JSX can become cluttered with long class lists

• Harder to understand for beginners unfamiliar with utility-first thinking

• Requires memorizing class names or frequent lookup

• Custom designs may need extending the config

Use it when: You need to move fast, prefer using pre-built utility classes, and want to reduce context-switching between JSX and CSS files. Excellent for startups, design systems, and prototyping.

🧱 BEM (Block Element Modifier)

BEM is a naming convention for writing CSS in a readable, scalable way. It's not tied to React, it works with plain CSS or preprocessors like Sass.

Example (with plain CSS):

Pros:

• Clear naming hierarchy and relationships

• Easy for large teams to follow and understand

• Works with any CSS preprocessor (SCSS, Less, etc.)

• Encourages reusable and maintainable CSS

Cons:

• Long and verbose class names

• No scoping by default, must be careful with global CSS

• Can get inconsistent without strict enforcement

Use it when: You are using global CSS or SCSS, want a structured system without additional libraries, and are working in a larger team where naming clarity is important.

📈 Performance Comparison (Brief)

Here’s how each method typically affects app performance and bundle size:

• Styled Components Adds a small runtime cost because styles are generated dynamically in JavaScript. Still performant for most apps, especially when used with Babel plugins that optimize it.

• CSS Modules Compiles down to simple class name mappings. It’s lightweight, fast, and doesn’t increase your JavaScript bundle size.

• Tailwind CSS Extremely efficient if set up correctly. Unused styles are purged during the build, making the final CSS file very small.

• BEM Pure CSS or SCSS-based. Performance depends on how much global CSS is written and whether it’s optimized (e.g. split by route or component).

🏁 Final Thoughts

Each method fits a different kind of project and team workflow.

Use Styled Components if you need dynamic styles and want to keep everything inside JavaScript. This is ideal for modern apps with theme support and reusable design systems.

Go with CSS Modules if you prefer classic CSS syntax and want automatic scoping without relying on JavaScript logic for styling.

Choose Tailwind CSS if you want to build user interfaces fast with utility classes and prefer not to manage separate style files.

Stick with BEM if you're writing plain CSS or SCSS and want a consistent naming system that everyone on your team can follow.

No method is wrong, just choose what helps you and your team stay productive, organized, and fast.

💬 Personally, I prefer using CSS Modules. They feel clean, easy to maintain, and keep my CSS readable and scoped without needing extra libraries. It strikes the perfect balance between structure and simplicity for most of my React projects.