How to Style a React Application – Different Options Compared

As a React developer, you have many choices when it comes to styling your applications. In this comprehensive guide, we‘ll dive deep into the most popular options, including pure CSS, CSS modules, preprocessors, CSS-in-JS libraries, utility-first frameworks, and component libraries. By the end, you‘ll have a clear understanding of the pros and cons of each approach and when to use them in your projects.

Styling with Pure CSS

Let‘s start with the most basic option – pure CSS. With this approach, you write plain CSS to style your React components, either in a separate stylesheet or inside a <style> tag. Here‘s an example of a styled component using pure CSS:

// MyComponent.js
import React from ‘react‘;
import ‘./MyComponent.css‘;

function MyComponent() {
  return (
    <div className="wrapper">
      <h1>Hello, world!</h1>
      <p>This is a styled component.</p>
    </div>
  );
}

export default MyComponent;

/* MyComponent.css */
.wrapper {
  background-color: #f0f0f0;
  padding: 20px;
  border-radius: 5px;
}

h1 {
  color: #333;
  font-size: 24px;  
}

p {
  color: #666;
}

The biggest benefit of pure CSS is its simplicity and familiarity. Every web developer knows CSS, and there‘s no extra tooling or setup required. Your styles will work in any browser, and you have complete control over your CSS.

However, pure CSS does have some drawbacks in larger codebases. Without a way to scope styles to specific components, it‘s easy to run into global class name clashes and specificity issues. Large projects can also end up with huge CSS files that are hard to maintain.

Scoped Styles with CSS Modules

CSS modules are a popular way to solve the scoping issue of pure CSS. With CSS modules, your styles are locally scoped by default, ensuring that class names are unique to each component. Here‘s the same component from before, but with CSS modules:

// MyComponent.js
import React from ‘react‘;
import styles from ‘./MyComponent.module.css‘;

function MyComponent() {
  return (
    <div className={styles.wrapper}>
      <h1>Hello, world!</h1>
      <p>This is a styled component.</p>
    </div>
  );
}

export default MyComponent;

/* MyComponent.module.css */
.wrapper {
  background-color: #f0f0f0;
  padding: 20px;
  border-radius: 5px;
}

.wrapper h1 {
  color: #333;
  font-size: 24px;
}

.wrapper p { 
  color: #666;
}

With CSS modules, each class name is transformed into a unique identifier (like MyComponent_wrapper_ab12) to avoid global clashes. You import the styles object into your component and reference the transformed class names.

The scoping provided by CSS modules helps keep your styles modular and reusable across components. It‘s easy to see which styles apply to each component. However, CSS modules do require an extra build step to work, and importing and referencing the transformed class names can get a bit verbose.

Enhancing CSS with Preprocessors

If you want to enhance your CSS with features like variables, nesting, and mixins, you can use a CSS preprocessor like Sass, Less, or PostCSS. Preprocessors extend the CSS language, letting you write more concise and maintainable stylesheets. Here‘s an example with Sass:

// MyComponent.scss
$primary-color: #333;
$secondary-color: #666;

.wrapper {
  background-color: #f0f0f0;
  padding: 20px;
  border-radius: 5px;

  h1 {
    color: $primary-color;
    font-size: 24px;
  }

  p {
    color: $secondary-color;
  }
}

// MyComponent.js 
import React from ‘react‘;
import ‘./MyComponent.scss‘;

function MyComponent() {
  return (
    <div className="wrapper">
      <h1>Hello, world!</h1>
      <p>This is a styled component.</p>
    </div> 
  );
}

export default MyComponent;

Preprocessors can make your CSS more readable and DRY by allowing you to nest selectors, define reusable variables and mixins, and more. Many developers find preprocessors easier to work with than plain CSS.

However, preprocessors do add complexity to your setup and require a build step to compile the processed CSS. There‘s also a learning curve if you‘re not familiar with the preprocessor‘s syntax. In general, preprocessors are a good choice for larger projects with complex styles, while pure CSS or CSS modules may suffice for simpler apps.

Embracing CSS-in-JS

For the ultimate in component-scoped styles, CSS-in-JS libraries let you write your CSS directly in your JavaScript code. The most popular CSS-in-JS library is styled-components. Here‘s how you would style a component with styled-components:

import React from ‘react‘;
import styled from ‘styled-components‘;

const Wrapper = styled.div`
  background-color: #f0f0f0;
  padding: 20px;
  border-radius: 5px;

  h1 {
    color: #333;
    font-size: 24px;
  }

  p {
    color: #666;
  }
`;

function MyComponent() {
  return (
    <Wrapper>
      <h1>Hello, world!</h1>
      <p>This is a styled component.</p>
    </Wrapper>
  );
}

export default MyComponent;

With styled-components, you create "styled" versions of DOM elements and write your CSS directly in a template literal. The CSS is scoped to that component, and you can even use props to dynamically change styles.

CSS-in-JS libraries are great for components with complex, dynamic styling needs. Your styles are tightly coupled with your components, and you can use the full power of JavaScript to dynamically generate CSS. However, this tight coupling can also make your components harder to reason about, and the inline CSS can clutter your component code. CSS-in-JS also requires a runtime library, which can slightly increase your bundle size.

Rapid Styling with Utility-First CSS

For developers who want to style their apps quickly without writing much custom CSS, utility-first frameworks like Tailwind CSS provide a set of pre-defined utility classes that you can compose to build out your UI. Here‘s an example component styled with Tailwind:

import React from ‘react‘;

function MyComponent() {
  return (
    <div className="bg-gray-100 p-4 rounded">
      <h1 className="text-gray-800 text-2xl">Hello, world!</h1>
      <p className="text-gray-600">This is a styled component.</p>
    </div>
  );
}

export default MyComponent;

Instead of writing your own CSS classes, you add pre-defined utility classes directly to your elements. Tailwind provides a comprehensive set of responsive utility classes for controlling layout, typography, colors, and more.

The benefit of utility-first CSS is that you can rapidly build out interfaces without context-switching between CSS and JSX. The pre-defined classes ensure consistent design and reduce the need for custom CSS. However, the downside is that your markup can become quite cluttered with long class names, and it‘s harder to create truly custom designs. Utility classes also aren‘t as reusable as CSS classes or components.

Quickly Styling with Component Libraries

Finally, if you want to build out interfaces quickly with pre-styled components, you can use a component library like Material-UI, Ant Design, or Chakra UI. These libraries provide a set of customizable, accessible UI components that you can drop into your app. Here‘s an example with Material-UI:

import React from ‘react‘;
import { Card, CardContent, Typography } from ‘@material-ui/core‘;

function MyComponent() {
  return (
    <Card>
      <CardContent>
        <Typography variant="h5">Hello, world!</Typography>
        <Typography variant="body1">This is a styled component.</Typography>
      </CardContent>
    </Card>
  );
}

export default MyComponent;

Instead of styling everything from scratch, you can use the pre-built Card, Typography, and other components to quickly create a polished UI. Component libraries enforce design consistency and handle tricky things like accessibility and responsiveness for you.

The tradeoff with component libraries is that your app may end up looking quite similar to others using the same library, and it can be harder to create fully custom designs. Component libraries can also significantly increase your bundle size if you‘re not careful about importing only the components you need.

Conclusion

As we‘ve seen, React developers have a plethora of options when it comes to styling their applications. From pure CSS to CSS-in-JS, preprocessors to component libraries, each approach has its own strengths and tradeoffs. Here‘s a quick summary:

• Pure CSS is simple and universal, but can lead to global scoping issues.
• CSS modules provide local scoping but require an extra build step.
• Preprocessors enhance CSS with variables and mixins but add complexity.
• CSS-in-JS allows dynamic, component-scoped styles, but can clutter code.
• Utility-first CSS provides rapid styling but can create class-heavy markup.
• Component libraries provide pre-styled components but may limit customization.

Ultimately, the "right" styling approach depends on your project‘s specific needs. For a simple app, pure CSS or CSS modules may suffice. For an app with complex, dynamic styles, a CSS-in-JS solution might work best. And for quickly building out an MVP, a utility-first framework or component library could be the way to go.

My advice? Experiment with different styling approaches to find the one that best fits your project and team. Each option we‘ve covered is a valid way to style a React app, and mastering more than one will make you a more well-rounded developer. Happy styling!