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Once UI is an open-source design system for React and Figma. It offers a flexible style system and a wide range of highly functional components. It also includes deployment-ready products for building a presence and monetizing from day one.

Once UI is not just a design system—it's a launchpad for creators. Whether you're a developer, designer, artist, or indie maker, we provide the tools and community to help you ship faster and stand out.

Once UI was built with simplicity and developer experience in mind. It's really easy to customize Once UI apps, and our products were designed to require the least amount of coding to launch. That said, Once UI has a very unique syntax that might take a bit of time to get familiar with if you're used to Tailwind and composable component libraries.

No. Once UI is a React design system and runs in any React app — Next.js, Vite, React Router, or your own setup. Next.js stays a first-class target: install the adapter from @once-ui-system/core/next and links route through next/link and images through next/image. Without it, components fall back to standard DOM. `next` is an optional peer dependency, so nothing is forced into your install.