Styled Components

Styled Components is a CSS-in-JS library that lets developers write actual CSS inside JavaScript using tagged template literals. Each styled component generates a unique class name automatically, eliminating naming collisions and ensuring styles are scoped to their component. Dynamic styling is a core feature, allowing CSS values to change based on component props.

The library extracts only CSS needed for rendered components and injects it into the page, meaning unused styles are never sent to the browser. Theming support through a ThemeProvider enables consistent design tokens across an application. For React developers, Styled Components aligns styling with the component model, keeping visual logic co-located with behavior. The tradeoff is a small runtime overhead compared to static CSS approaches, and debugging can be less intuitive since generated class names are not human-readable without the Babel plugin that adds component names.