CSS Modules vs Stylus: What are the differences?

Introduction

In this article, we will discuss the key differences between CSS Modules and Stylus. Both of these technologies are commonly used for styling websites, but they have distinct features that set them apart.

1. Scoping: CSS Modules support local scoping of styles, where class names are automatically generated in a way that they are unique within a component. This ensures that styles defined in one component do not clash with styles in another component. On the other hand, Stylus does not have built-in scoping capabilities and relies on naming conventions or other mechanisms to avoid style conflicts.

2. Syntax and Features: CSS Modules follow standard CSS syntax, with the addition of being able to import and use variables, compose classes, and apply pseudo-selectors and media queries. In contrast, Stylus introduces a different syntax with features like nested selectors, variable interpolation, and mixins that can significantly improve the readability and maintainability of stylesheets.

3. Compilation: CSS Modules are compiled at build-time, where the styles are transformed into unique class names and associated with their respective components. This results in separate CSS files being generated for each component. On the other hand, Stylus is a preprocessor that compiles into CSS before the website is deployed. This means that the styles are compiled just once, reducing the overhead during runtime.

4. Browser Support: CSS Modules are inherently compatible with all modern browsers, as they ultimately generate standard CSS. Stylus, however, requires a compiler or transpiler to convert its syntax into CSS that browsers can understand. This introduces an additional step in the development process and might have implications for older browsers or other environments with limited support for CSS preprocessors.

5. Community and Ecosystem: CSS Modules have gained significant adoption and have a larger community of developers sharing code, best practices, and tools. This makes it easier to find resources and get support when working with CSS Modules. Stylus, while still popular, has a smaller community and fewer resources available, which may limit the number of plugins or integrations available for specific use cases.

6. Learning Curve: CSS Modules have a relatively low learning curve, as they are built on top of standard CSS syntax. Developers familiar with CSS can easily adopt CSS Modules without needing to learn a new syntax. On the other hand, Stylus introduces a new syntax and concepts that developers need to learn before they can start using it effectively. This can be an advantage for more experienced developers looking for advanced features, but it might require additional time and effort for beginners.

In summary, CSS Modules provide local scoping, follow standard CSS syntax, are compiled at build-time, have broader browser support, a larger community, and a lower learning curve compared to Stylus, which has a different syntax, supports nested selectors and mixins, compiles into CSS at runtime, requires additional tools for browser compatibility, has a smaller community, and may have a steeper learning curve.