kitio.aiSentry vs 21st.dev
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Sentry starts at See pricing page and 21st.dev starts at See pricing page. 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
- Error monitoring
- Tracing and profiling
- Session replay
- Seer AI debugging agent
- AI code review
- Sentry MCP server
- Component library
- Magic MCP server
- UI variation generation
- Agent-ready prompts
- shadcn compatibility
| Feature | Sentry | 21st.dev |
|---|---|---|
| Best for | Error and performance monitoring with an AI debugging agent | UI component library and MCP tools for AI coding agents |
| Category | Coding | Coding |
| Pricing model | Freemium | Freemium |
| Starting price | See pricing page | See pricing page |
| Free plan | Yes | Yes |
| Made by | Functional Software (Sentry) | 21st.dev |
| Based in | United States | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
Sentry starts at See pricing page and 21st.dev starts at See pricing page. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
4 plans
Developer
Free
- Limited to one user
- Error monitoring and tracing
- 10 custom dashboards
- MCP access
Team
$26/mo billed yearly
- Unlimited users
- Third-party integrations
- 20 custom dashboards
- Seer available as add-on
Business
$80/mo billed yearly
- Unlimited custom dashboards
- Advanced quota management
- SAML and SCIM support
Enterprise
Contact sales
- Technical account manager
- Dedicated support
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
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
Sentry
- Free plan for solo developers
- AI debugging works from real error data
- Wide SDK coverage
- Integrates with GitHub and Slack
- Seer needs a separate subscription
- Free plan is limited to one user
- Costs rise with event volume
21st.dev
- Improves AI-generated UI quality
- Works with major coding agents
- Large free catalog
- React and Tailwind only
- Magic usage is paid
Which one should you choose?
Choose Sentry if you want:
- Free plan for solo developers
- AI debugging works from real error data
- Wide SDK coverage
Watch out: seer needs a separate subscription.
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.
Sentry vs 21st.dev FAQ
What is the difference between Sentry and 21st.dev?
Sentry: Error and performance monitoring with an AI debugging agent. 21st.dev: UI component library and MCP tools for AI coding agents. Both are coding tools.
Is Sentry or 21st.dev cheaper?
Sentry starts at See pricing page and 21st.dev starts at See pricing page. Check both pricing pages for current plans.
Do Sentry and 21st.dev have free plans?
Sentry: Yes. 21st.dev: Yes.
Who makes Sentry?
Sentry is made by Functional Software (Sentry), based in United States.
Who makes 21st.dev?
21st.dev is made by 21st.dev.
Which should I choose, Sentry or 21st.dev?
Choose Sentry if you value free plan for solo developers and ai debugging works from real error data. Choose 21st.dev if you value improves ai-generated ui quality and works with major coding agents.