Updated April 29, 2026
21st.dev is the largest React component registry for the agentic internet — an open-source, community-driven marketplace of shadcn/ui-based React + Tailwind components, blocks, and hooks. 1.4M developers (200K MAU), pivoting into a full agent deployment SDK.
AWS-backed open-source agentic SDK for building AI agents
Core capabilities each platform advertises.
StrandsWhat each tool does well, and the limitations to keep in mind.
Pros
Cons
StrandsPros
Cons
Saves so much time — broad set of high-quality, free components, including 3D. Smooth React and Next.js integration.
Read full reviewStrandsChoose 21st.dev if you wantChoose if you want
Choose Strands if you wantChoose if you want
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