Overview

Rating

10.0 / 10

Rating

Best For

React developers and AI app builders who want shadcn/ui-quality components and emerging agent deployment infrastructure

Best For

Solo developers and small teams who use AI agents daily and want one that learns and compounds over time

Product Summary

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.

Product Summary

Hermes Agent is Nous Research's open-source autonomous AI agent with persistent memory across sessions. Released February 2026; hit 95.6K GitHub stars in seven weeks. Memory persists in ~/.hermes/memories/ plus 8 external provider plugins (Mem0, Honcho, OpenViking, etc.). Self-creates skills that compound over months of use.

Starting Price

$0Per forever

Starting Price

$0Per forever

Free Trial

Yes

Free Trial

Yes

Free Version

Yes

Free Version

Yes

Website

21st.dev

Website

nousresearch.com

Key features

Core capabilities each platform advertises.

21st.dev

Largest React component registry — shadcn/ui + Tailwind based
Open-source and community-driven — npm-like CLI install
Components, blocks, hooks, and full marketing/app templates
AI Agent Registry pivoting toward full agent deployment SDK
200K monthly actives, 1.4M+ developers using it

Hermes Agent

Persistent memory across sessions in ~/.hermes/memories/
8 external memory provider plugins (Mem0, Honcho, OpenViking, etc.)
Self-generates and reuses skills from past tasks
Layered MEMORY.md + USER.md system-prompt injection
Open-source — 95.6K GitHub stars in 7 weeks

Strengths and tradeoffs

What each tool does well, and the limitations to keep in mind.

21st.dev

Pros

Largest registry of high-quality, free shadcn/ui components
Smooth React + Next.js integration
Active community contribution model
Strong fit for AI-driven workflows
YC-backed with credible pivot toward agent infrastructure

Cons

Quality varies across community-contributed components
Pricing for the agent SDK side is still unclear
shadcn/ui-only — limited if your stack uses a different UI kit
Newer than incumbent component libraries (MUI, Chakra)

Hermes Agent

Pros

Best-in-class persistent memory across sessions
Auto-generated skills that compound 40% speed gains over time
Open-source under Apache 2.0 — fully self-hostable
Growing ecosystem of 8+ external memory providers
Fastest-growing agent framework of 2026

Cons

What people are saying

21st.dev

Esme PatelProduct Hunt

Saves so much time — broad set of high-quality, free components, including 3D. Smooth React and Next.js integration.

Read full review

Hermes Agent

TokenMix reviewTokenMix Blog

Released February 2026; seven weeks later it hit 95,600 GitHub stars — the fastest-growing agent framework of 2026.

Read full review

21st.dev or Hermes Agent — which should you choose?

Choose 21st.dev if you wantChoose if you want

Rapid React + Tailwind UI prototyping for AI apps
shadcn/ui component discovery and installation
Marketing site assembly from pre-built blocks
AI-generated dashboards and chart UIs
Future: agent-runtime deployment via 21st SDK

Choose Hermes Agent if you wantChoose if you want

Long-running personal AI assistant that learns your preferences
Solo developer power-use scenarios where memory compounds
Research and exploration tasks with knowledge accumulation
Project-aware coding workflows across many sessions
Self-hosted private agent with full data ownership

Compare 21st.dev and Hermes Agent on your own traffic

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21st.dev vs Hermes Agent (2026)

Overview

Key features

Strengths and tradeoffs

What people are saying

21st.dev or Hermes Agent — which should you choose?

Compare 21st.dev and Hermes Agent on your own traffic

Frequently Asked Questions

Other popular comparisons

21st.dev vs Hermes Agent (2026)

Overview

Key features

Strengths and tradeoffs

What people are saying

21st.dev or Hermes Agent — which should you choose?

Compare 21st.dev and Hermes Agent on your own traffic

Frequently Asked Questions

What is an AI agent framework?

Do I need a framework or can I build agents with raw API calls?

Which agent framework should I choose?

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