Styled-components and @emotion/react are the two dominant CSS-in-JS libraries for React applications, both enabling component-scoped styling with JavaScript. Styled-components pioneered the tagged template literal approach to styling React components, while Emotion emerged as a performance-focused alternative that offers multiple styling APIs including both styled components and a CSS prop.
This comparison matters because choosing between them impacts your bundle size, runtime performance, React 18+ compatibility, and developer experience. Styled-components targets teams who prefer a consistent component-driven API with extensive community resources, while Emotion appeals to developers prioritizing flexibility, performance optimization, and forward compatibility with React's Concurrent mode.
Choose @emotion/react for new projects unless you have specific reasons not to. It offers superior performance, smaller bundle size, React 18 compatibility, and API flexibility without sacrificing features. The only meaningful advantage styled-components holds is its larger community, which matters primarily for finding existing solutions to niche problems. However, Emotion's higher npm download count and comprehensive documentation mitigate this concern for most teams.
Styled-components remains viable for existing codebases where migration costs outweigh benefits, or for teams that strongly prefer its exclusive tagged-template approach. But the lack of React Concurrent mode support is a significant technical debt that will become increasingly problematic as the React ecosystem moves forward. For greenfield projects, teams building performance-sensitive applications, or codebases planning to use React 18+ features, Emotion is the clear technical choice.