Radix Primitives

Radix Primitives (also referred to as Radix UI) is a headless component library for React. Being headless, it means that Radix Primitives doesn't ship with any styling, but rather a set of components that have been built to be accessible and composable, meaning it is an ideal choice for building custom design systems and styled component libraries in which the developer only has to take care of the styling.

Radix Primitives has since its release in late 2020 become a stable library in the React ecosystem and is the technology behind awesome libraries such as the popular shadcn/ui library built on top of Radix UI and Tailwind CSS.

In August 2023 the Radix team announced Radix Themes, a component library built on top of Radix Primitives which, unlike Radix Primitives, ship with a flexible styling system which allow theming via CSS variables.