21st.dev
Actively usedAI-native UI inspiration and components for React — discover and ship polished interface blocks and patterns faster.
About 21st.dev
21st.dev is a catalogue of React interface blocks — the sections you build over and over, already designed and ready to drop in. It is AI-native in the practical sense: components are structured so a coding agent can pull one in and adapt it, rather than you copying out of a documentation page by hand. Most product surfaces are largely conventional, and the conventional part should not consume a week.
It is in active use here. We reach for it when we need a block we have already built a dozen variants of — pricing tables, hero sections, navigation, feature grids. We treat it as a starting point rather than a dependency: take the block, strip what we do not need, make it match the rest of the system, move on.
shadcn/ui sits underneath much of this and is the better answer when you want primitives to build on rather than finished sections. Aceternity UI overlaps directly and leans more animated, which suits marketing pages. Tailwind UI is the polished, commercially licensed option if you want curated consistency. MUI, Chakra and Mantine solve a different problem — a versioned component system with theming, which is what a large app with many contributors needs. 21st.dev is right for shipping a specific block fast. It is wrong as the foundation of a design system.
Try 21st.dev yourself.
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21st.dev alternatives
Other UI Components tools we use alongside 21st.dev.
shadcn/ui
Re-usable component patterns built with Radix UI and Tailwind CSS — copy, paste, and own the code in your Next.js or React app.
View toolAceternity UI
Animated React components for landing pages — copy-paste blocks built with Tailwind CSS and Framer Motion, with Next.js and dark mode support.
View toolMotion.dev
Production-grade web animation library for React, JavaScript, and Vue — scroll-linked motion, gestures, layout transitions, spring physics, and agent-compatible docs.
View tool
Frequently asked questions
- What is 21st.dev?
- AI-native UI inspiration and components for React — discover and ship polished interface blocks and patterns faster. 21st.dev is a catalogue of React interface blocks — the sections you build over and over, already designed and ready to drop in. It is AI-native in the practical sense: components are structured so a coding agent can pull one in and adapt it, rather than you copying out of a documentation page by hand. Most product surfaces are largely conventional, and the conventional part should not consume a week.
- What category does 21st.dev fall into?
- 21st.dev is a UI Components tool. Replace Works tracks it in the Tool Stack, our public catalogue of the AI tools we evaluate and ship with.
- What are the best alternatives to 21st.dev?
- The closest alternatives we track in the same UI Components category are shadcn/ui, Aceternity UI and Motion.dev. All of them are listed in the Replace Works Tool Stack with our notes on where each one fits.
- Does Replace Works use 21st.dev?
- Yes. 21st.dev is in active rotation at the studio and we use it on client work.