21st
UI building blocks for the agentic internet
Serafim Korablev, Sergey Bunas · 2 co-founders
Profile coverage4 of 8 · missing Funding, Signals, Customers, Stack / tools · last run 8/8/2026
About
21st.dev is the largest React component registry for AI applications, used by 2M developers We provide the building blocks to create agent-powered apps: UI components, agent templates.