CSS-in-JS: Styled Components vs Emotion
The world of web development is constantly evolving, and with it, the ways we approach styling our applications. Among the many techniques that have emerged, CSS-in-JS has gained immense popularity for its ability to tackle styling in a component-centric manner. Two of the leading libraries in this space are Styled Components and Emotion. In this article, we will explore these two libraries, compare their features, advantages, and use cases, and provide examples to help you decide which one might be the best fit for your project.
Understanding CSS-in-JS
CSS-in-JS is a pattern where CSS is written within JavaScript files. This approach allows developers to scope styles to components, enhancing maintainability and reducing the risk of style conflicts. In modern frameworks like React, CSS-in-JS libraries have become invaluable, enabling both styling and component logic to reside in the same file.
What is Styled Components?
Styled Components is one of the most popular CSS-in-JS libraries. It allows developers to use tagged template literals to style their components, providing an elegant and expressive way to handle CSS. This library takes advantage of the power of ES6 syntax and the full capabilities of JavaScript.
Key Features of Styled Components
- Dynamic Styling: Style components based on props, enabling responsive and conditional styles.
- Theming: Easily manage themes with a ThemeProvider and styled components that can reference theme values.
- Automatic Vendor Prefixing: Styled Components automatically adds vendor prefixes, ensuring compatibility across different browsers.
Example Usage
Here’s a simple example of how to create a styled button with Styled Components:
import styled from 'styled-components';
const Button = styled.button`
background-color: ${(props) => props.primary ? 'blue' : 'gray'};
color: white;
padding: 10px 20px;
border: none;
border-radius: 5px;
cursor: pointer;
&:hover {
background-color: ${(props) => props.primary ? 'darkblue' : 'darkgray'};
}
`;
const App = () => (
<div>
<Button primary>Primary Button</Button>
<Button>Secondary Button</Button>
</div>
);
What is Emotion?
Emotion is another powerful library in the CSS-in-JS landscape. It focuses on providing high performance and flexibility in styling components. Emotion offers two major ways to style components: using the `css` prop and using styled components, similar to what Styled Components offers.
Key Features of Emotion
- Performance: Optimized for performance and minimal overhead, making it an excellent choice for large applications.
- Flexible Styling: Offers both the `css` prop for quick styling and styled components for a declarative approach.
- Server-Side Rendering: Built-in support for server-side rendering to improve page load times.
Example Usage
Here’s how you can style a button using Emotion:
/** @jsxImportSource @emotion/react */
import { css } from '@emotion/react';
const buttonStyle = (primary) => css`
background-color: ${primary ? 'blue' : 'gray'};
color: white;
padding: 10px 20px;
border: none;
border-radius: 5px;
cursor: pointer;
&:hover {
background-color: ${primary ? 'darkblue' : 'darkgray'};
}
`;
const App = () => (
<div>
<button css={buttonStyle(true)}>Primary Button</button>
<button css={buttonStyle(false)}>Secondary Button</button>
</div>
);
Performance Comparison
When it comes to performance, both Styled Components and Emotion have optimizations that cater to different needs. Emotion’s approach to performance is well-suited for larger applications, where the reduced runtime and bundle size can significantly impact load times. Styled Components, while slightly heavier, provides excellent abstractions and is generally performant for most mid-sized applications.
Theming Capabilities
Theming is a critical consideration when building modern UI applications. Both libraries offer powerful theming options. Styled Components provides a `ThemeProvider` for theming applications easily, while Emotion also allows the usage of context for theme management.
Styled Components Them Example
import { ThemeProvider } from 'styled-components';
const theme = {
primary: 'blue',
secondary: 'gray',
};
const Button = styled.button`
background-color: ${(props) => props.theme.primary};
`;
const App = () => (
<ThemeProvider theme={theme}>
<Button>Themed Button</Button>
</ThemeProvider>
);
Emotion Theming Example
import { ThemeProvider } from '@emotion/react';
const theme = {
primary: 'blue',
secondary: 'gray',
};
const buttonStyle = (primary) => css`
background-color: ${primary ? theme.primary : theme.secondary};
`;
const App = () => (
<ThemeProvider theme={theme}>
<button css={buttonStyle(true)}>Themed Button</button>
</ThemeProvider>
);
Community and Ecosystem
Both Styled Components and Emotion have strong community support and a rich ecosystem. Styled Components has a wide array of community-created extensions and tools, while Emotion is also rapidly growing with contributions and plugins. Your choice may come down to the specific needs and existing integrations you have in your project.
When to Choose Which?
Choosing between Styled Components and Emotion often depends on your project’s requirements:
- Use Styled Components if:
- You prefer a more opinionated approach with a rich syntax for styling.
- You are focused on building small to mid-sized applications.
- You appreciate the automatic vendor prefixing and theming capabilities.
- Use Emotion if:
- You need greater performance and flexibility, especially for larger applications.
- You prefer a less opinionated library and want to use both styled components and the css prop.
- You are focusing on optimizing load times and server-side rendering.
Conclusion
CSS-in-JS libraries like Styled Components and Emotion bring a powerful approach to component styling in modern web applications. While both have unique strengths and capabilities, your choice between the two will hinge on your project requirements and personal preferences. Experiment with both to see which aligns better with your workflow, and leverage their features to create stunning and maintainable UIs.
Ultimately, whether you choose Styled Components or Emotion, you’re adopting a modern CSS approach that enhances the way you build applications.
