21st.dev

What is 21st.dev?

21st.dev is a community-driven component library and design marketplace for building AI-powered websites, created by the 21st team. It functions as a curated catalog of production-ready UI components built with modern web technologies, allowing developers and designers to browse, customize, and integrate pre-built interface elements into their projects without starting from scratch.

The platform hosts thousands of categorized components spanning foundational elements (buttons, inputs, modals, cards) and specialized sections (AI chat interfaces, pricing sections, heroes, testimonials). Each component is tagged by category and popularity, with over 130 button variations, 73 hero sections, 62 select menus, 40 accordions, and 30+ AI chat component templates available. Components are filterable by featured, newest, and best-performing options, enabling users to discover high-quality designs quickly. The library emphasizes visual design alongside functionality, making it particularly useful for teams building conversational AI applications that need polished chat interfaces and modern aesthetics.

21st.dev operates on a freemium model where users can view and copy component code at no cost, with premium features likely supporting advanced filtering, version control, or team collaboration. The platform leverages community contributions—developers can submit components to be featured, creating a crowdsourced design system. This approach combines elements of GitHub's open-source model with Pinterest's visual discovery interface, allowing non-technical stakeholders to browse designs while developers access underlying code.

The tool integrates with standard web development workflows, supporting frameworks commonly used in AI web applications. Users range from indie developers prototyping AI tools to design teams at startups building customer-facing interfaces. The component library significantly reduces development time for UI-heavy projects, particularly for teams