CSS-in-JS vs CSS Modules: Which Should You Choose?
Compare CSS-in-JS and CSS Modules on component styling, performance and maintainability. Discover which approach fits your frontend best.
CSS-in-JS offers more dynamics and colocation; CSS Modules is lighter and closer to standard CSS. The trend favors CSS Modules or utility-first (Tailwind).
CSS-in-JS
Styles written in JavaScript and injected (e.g. styled-components, Emotion).
CSS Modules
CSS files with locally scoped class names that are automatically unique.
What are the key differences between CSS-in-JS and CSS Modules?
| Feature | CSS-in-JS | CSS Modules |
|---|---|---|
| Colocation | Styles in same file as component | Separate .module.css per component |
| Dynamic styling | Props and themes directly in JS | Variables or class switching needed |
| Bundle size | Runtime, often larger | Zero runtime, CSS only |
| Learning curve | React-specific, more concepts | Standard CSS, simpler |
What is the verdict on CSS-in-JS vs CSS Modules?
CSS-in-JS offers more dynamics and colocation; CSS Modules is lighter and closer to standard CSS. The trend favors CSS Modules or utility-first (Tailwind).
Which option does MG Software recommend?
MG Software uses CSS Modules or Tailwind where possible for better performance. CSS-in-JS remains suitable for complex theming and design systems.
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