21st.dev vs. Flowbite vs. Headless UI vs. JavaScript Comparison Chart

21st.dev is an open source community registry of React UI components, enabling design engineers to ship polished user interfaces more efficiently. Inspired by shadcn/ui, it offers ready-to-use React Tailwind components that can be installed with a single command using npx shadcn. The platform provides a comprehensive collection of UI elements, including accordions, alerts, avatars, badges, buttons, calendars, cards, carousels, checkboxes, dialogs, dropdowns, forms, icons, inputs, menus, notifications, pagination, popovers, radio groups, selects, sidebars, sliders, tables, tabs, tags, text areas, toasts, toggles, and tooltips. Additionally, it features landing page components such as announcements, backgrounds, borders, call-to-actions, client sections, comparisons, docks, features, footers, hero sections, image galleries, maps, navigation menus, pricing tables, scroll areas, testimonials, text blocks, and video sections.

​Headless UI is a library of completely unstyled, fully accessible UI components designed to integrate seamlessly with Tailwind CSS. It offers a range of components for both React and Vue. These components are built with accessibility in mind, adhering to WAI-ARIA design patterns and providing full keyboard navigation support. Because they are unstyled by default, developers have complete control over the look and feel, allowing for easy customization to match any design system. Headless UI components expose state information through data attributes and render props, enabling developers to conditionally apply styles based on component states such as focus, open, selected, or disabled. This approach ensures that the components are both flexible and accessible, making them suitable for building custom, high-quality user interfaces. With Headless UI, developers can create complex UI elements like modals, dropdowns, and tabs without sacrificing accessibility or design flexibility.