StyleX vs Material UI: A Comparative Insight

In the world of front-end development, style libraries play an essential role in enabling developers to create responsive, consistent, and visually appealing interfaces. As a senior UI/UX designer, you are no stranger to the challenge of balancing design consistency, user experience, and performance across various devices. Two popular styling solutions that cater to these demands are StyleX and Material UI. While both offer powerful ways to style React applications, their underlying philosophies and practical applications differ significantly.

In this blog post, we will delve into the key differences between StyleX and Material UI, explore their use cases, and discuss when to use one over the other. We will also provide code examples to illustrate their functionalities, so you can make an informed decision when choosing the right styling solution for your next project.

What is StyleX?

StyleX is Facebook’s internal CSS-in-JS solution, which they have recently made public. It aims to offer a highly performant and modular system for writing CSS in JavaScript, particularly in React applications. The key idea behind StyleX is that it emphasizes runtime performance by generating minimal, atomic CSS rules that ensure fast rendering of styled components.

Key Features of StyleX:

Atomic CSS Generation: StyleX breaks down styles into the smallest units possible, minimizing CSS file size and avoiding redundant rules.
Scoped Styles: Styles defined with StyleX are locally scoped to a component, avoiding naming collisions and ensuring predictable behavior.
Dynamic Style Composition: Developers can dynamically compose styles based on component states, such as hover or focus, by simply combining style objects.
Optimized for Performance: StyleX generates and applies CSS at runtime, ensuring only the necessary styles are injected into the DOM.

Code Example of StyleX:

import { createStyle } from 'stylex';

const styles = createStyle({
  button: {
    padding: '10px 20px',
    backgroundColor: 'blue',
    color: 'white',
    borderRadius: '5px',
  },
  buttonHover: {
    backgroundColor: 'darkblue',
  },
});

function StyledButton({ label }) {
  return (
    <button
      className={styles.button}
      onMouseOver={() => styles.buttonHover}
    >
      {label}
    </button>
  );
}

The above example illustrates how StyleX provides scoped, performance-optimized styling by splitting the button’s style properties into individual atomic classes.

What is Material UI?

Material UI (MUI) is one of the most popular React UI libraries, inspired by Google’s Material Design principles. It provides pre-built components, theming support, and a robust styling solution via CSS-in-JS. Material UI aims to deliver a comprehensive toolkit for building consistent, accessible, and aesthetically pleasing interfaces out of the box.

Key Features of Material UI:

Pre-Built Components: Material UI offers a wide range of components (buttons, dialogs, form elements) that follow Material Design guidelines, allowing for rapid UI development.
Customizable Themes: MUI comes with theming support, enabling developers to create consistent design systems with light and dark modes, custom palettes, and typography.
CSS-in-JS via Emotion or Styled Components: Material UI leverages Emotion (by default) to provide CSS-in-JS capabilities, allowing you to style components inline with your React code.
Accessibility and Responsiveness: MUI components are accessible out of the box, with responsive breakpoints and well-structured ARIA support.

Code Example of Material UI:

import React from 'react';
import { Button } from '@mui/material';

function StyledButton() {
  return (
    <Button variant="contained" color="primary">
      Click Me
    </Button>
  );
}

export default StyledButton;

In this example, Material UI allows you to easily integrate pre-styled components like the Button, which adheres to Material Design guidelines and can be further customized through the theme or sx prop.

Comparing StyleX and Material UI

1. Styling Approach: Atomic vs. Component-Based

StyleX emphasizes atomic CSS, meaning each style property is broken down into minimal rules that can be dynamically composed. This results in minimal CSS injection and avoids the redundancy of repeating style definitions. Material UI, on the other hand, uses a more component-based approach where styles are applied to entire components via classes or inline styles, leveraging Emotion or Styled Components for CSS-in-JS.

StyleX: Highly granular control over CSS, but may require more effort to manage styles manually.
Material UI: Easier to use with pre-built components, but generates larger style sheets compared to StyleX.

2. Performance: Runtime Optimization vs. Readiness

One of the key selling points of StyleX is its focus on runtime performance. By generating atomic classes, it reduces the amount of CSS that needs to be injected into the DOM. This leads to faster load times and reduced CSS bloat. Material UI, while performant in many scenarios, tends to generate more CSS due to its comprehensive nature and reliance on larger component libraries.

StyleX: Best suited for performance-critical applications with minimalistic styling needs.
Material UI: Ideal for rapid development of feature-rich applications, but comes with a higher CSS overhead.

3. Flexibility: Customization vs. Convention

StyleX offers greater flexibility for developers who prefer to define their styling at a granular level. It is unopinionated, meaning you have full control over the design, but it also means you have to put more effort into defining consistent styles. Material UI, on the other hand, provides design conventions via Material Design guidelines, which makes it easier to build consistent UIs without much effort.

StyleX: Offers high flexibility for custom designs but requires more manual work.
Material UI: Enforces Material Design conventions but is customizable through theming and styled components.

4. Use Cases: When to Choose StyleX or Material UI

Choose StyleX when performance is a priority, such as in complex applications with many interactive components that need to render quickly. If you prefer a low-level approach to styling without relying on a component library, StyleX is the better choice.
Choose Material UI if you need a comprehensive, out-of-the-box solution for building user interfaces based on Material Design. It is perfect for prototyping or for projects that need to scale quickly with pre-built components and themeable options.

Practical Application: Hybrid Approach?

While StyleX and Material UI cater to different needs, in certain cases, you can use them together. For example, you can leverage Material UI’s pre-built components for common UI elements and use StyleX for fine-tuning or highly performance-critical parts of your application. Combining these approaches gives you the best of both worlds: rapid development with Material UI and granular control with StyleX.

Conclusion

As a senior UI/UX designer, understanding the strengths and trade-offs between StyleX and Material UI will empower you to make more informed decisions when selecting a styling solution. StyleX provides excellent performance optimizations and flexibility, while Material UI offers rapid development with a robust component library that adheres to Material Design principles. Depending on the needs of your project, either tool—or even a combination of both—could serve as the ideal choice.

When performance, customization, and control are critical, StyleX will shine. However, for projects requiring quick implementation of a polished, Material Design-compliant UI, Material UI remains a go-to choice.

Happy designing!