kitio.ai21st.dev vs HoundDog.ai
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. 21st.dev starts at See pricing page and HoundDog.ai starts at $200/yr. Check both pricing pages for current plans.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Component library
- Magic MCP server
- UI variation generation
- Agent-ready prompts
- shadcn compatibility
- Privacy code scanner
- GDPR data mapping
- Dataflow context engine
- CI integration
- Shadow AI discovery
- MCP servers
| Feature | 21st.dev | HoundDog.ai |
|---|---|---|
| Best for | UI component library and MCP tools for AI coding agents | Privacy code scanner and dataflow context for AI coding agents |
| Category | Coding | Coding |
| Pricing model | Freemium | Freemium |
| Starting price | See pricing page | $200/yr |
| Free plan | Yes | Yes |
| Made by | 21st.dev | HoundDog.ai |
| Based in | – | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
21st.dev starts at See pricing page and HoundDog.ai starts at $200/yr. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
4 plans
Free
Free
- Browse the whole library
- 2 component copies a day
Builder
$8/mo billed quarterly
- Unlimited copies and installs
- Unlimited shaders and gradients
Builder + AI
$20/mo billed quarterly
- 500 AI credits/month
- Design Bug Bot PR reviews
- Premium AI models
Team
$10/seat/mo billed quarterly
- Per seat, 2 to 50 seats
- Shared collections
- Private team components
- Admin controls
2 plans
Free
Free
- CLI scans on demand
- Automated CI setup
- Local Markdown report
Enterprise
$200/yr
- Per developer
- Cloud or on-premises
- SSO, RBAC and audit logs
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
21st.dev
- Improves AI-generated UI quality
- Works with major coding agents
- Large free catalog
- React and Tailwind only
- Magic usage is paid
HoundDog.ai
- Free scanner distributed through GitHub
- Evidence tied to actual code
- Cloud or on-premises option
- Scanner is not open source
- Enterprise tier is priced per developer
- GraphQL and REST support still coming
Which one should you choose?
Choose 21st.dev if you want:
- Improves AI-generated UI quality
- Works with major coding agents
- Large free catalog
Watch out: react and tailwind only.
Choose HoundDog.ai if you want:
- Free scanner distributed through GitHub
- Evidence tied to actual code
- Cloud or on-premises option
Watch out: scanner is not open source.
21st.dev vs HoundDog.ai FAQ
What is the difference between 21st.dev and HoundDog.ai?
21st.dev: UI component library and MCP tools for AI coding agents. HoundDog.ai: Privacy code scanner and dataflow context for AI coding agents. Both are coding tools.
Is 21st.dev or HoundDog.ai cheaper?
21st.dev starts at See pricing page and HoundDog.ai starts at $200/yr. Check both pricing pages for current plans.
Do 21st.dev and HoundDog.ai have free plans?
21st.dev: Yes. HoundDog.ai: Yes.
Who makes 21st.dev?
21st.dev is made by 21st.dev.
Who makes HoundDog.ai?
HoundDog.ai is made by HoundDog.ai.
Which should I choose, 21st.dev or HoundDog.ai?
Choose 21st.dev if you value improves ai-generated ui quality and works with major coding agents. Choose HoundDog.ai if you value free scanner distributed through github and evidence tied to actual code.