Is 21st.dev worth it?
21st.dev is worth a look for React developers who build UI with AI agents.
This 21st.dev review is based on the company's own pages. The library is large, with 12,000+ components plus templates, themes, icons and shaders, all in React, TypeScript and Tailwind. You copy a prompt into your agent or install through the CLI or MCP, and the code becomes source you own. Paid plans start at $6 per month billed yearly, but every payment is non-refundable.
What is 21st.dev?
21st.dev is a UI component library and marketplace run by 21st Labs Inc.
What 21st.dev offers
The site collects components, templates, themes, icons, shaders and open-source apps from many design engineers. The library lists 12,000+ components, 371 templates, 969 themes, 29,000 icons, 617 shaders and 138 apps. Because many authors contribute, the styles vary rather than following one kit. Categories range from animated heroes and backgrounds to buttons, AI chats, forms, cards and navigation menus.
How it fits AI coding workflows
Each component has a Copy prompt button. You paste the prompt into Claude Code, Cursor, Codex or Lovable, and the agent builds the component in your codebase using your theme. Every component also has a shadcn CLI command, so you can install it without an agent. The same company runs a separate 21st Agents platform.
Is 21st.dev legit and safe to use?
21st Labs Inc. publishes a registered address and clear marketplace rules.
Company and scale
21st Labs Inc. is a Delaware corporation with a registered address in Dover, Delaware, United States. The site footer says it is backed by YC. It claims 4,581,161 builders, including teams at ByteDance, Shopify, Google and NVIDIA.
Licensing and payments
Publishers must own or hold the rights to what they upload, and items reported as licence violations or missing attribution are removed. On billing, you can cancel anytime and keep access to the end of the period, but the terms state that payments for plans and credit packs are non-refundable, including after non-use or accidental purchase.
How we evaluated 21st.dev
Toolavero based this review on published information only.
We read the tool's own pages: the homepage, the pricing page with its plan comparison and FAQ, component category pages, the privacy policy and the terms of service. Every claim here comes from those pages. Toolavero did not sign up for an account, copy components, or test 21st AI or Design Bug Bot, so we cannot judge code quality first-hand. Topics the pages do not cover are left out.
21st.dev output quality and limits
Quality depends on the individual author of each component, but the technical format is consistent.
Stack and compatibility
Components are React and TypeScript with Tailwind CSS, published in the shadcn registry format. They run anywhere React runs, including Next.js, Vite, Remix and Astro. Since the code lands as source in your repo, you can edit it like any other file.
Privacy and security
The privacy policy says 21st does not use customer prompts, completions or agent conversations to train its own models without explicit consent. Data is encrypted in transit with TLS 1.2 or higher and at rest on supported subprocessors. The company says it is pursuing SOC 2 attestation, so it is not yet complete.
21st.dev key features
Beyond the library, 21st.dev adds AI generation, design review and developer tooling.
21st.dev MCP and CLI
21st MCP connects the library to Cursor, Claude Code, Windsurf, VS Code and any MCP client, so your agent can search and install pieces without leaving the editor. In the terminal, npx @21st-dev/cli add drops the source into your repo.
21st AI and Design Bug Bot
21st AI generates components that are not in the library and can compare takes from several models side by side. Design Bug Bot reviews pull requests for contrast, spacing and layout bugs and offers fix code. Both use AI credits.
Shader Builder
Shader Builder lets you tune shaders, gradients and ASCII art in your own colours, then copy the code.
21st.dev pricing and plans
There is a free plan and three paid tiers, billed quarterly or yearly, with yearly saving 25 %.
Free is $0 forever, with the full library, 2 copies a day and 5 Design Bug Bot reviews. Builder is $6 per month billed yearly, $72, and removes the copy limit. Builder + AI is $15 per month billed yearly, $180, with 500 credits a month and options of 1,000 or 2,000. Extra credits cost $5 for 100 and roll over.
Team is $7.50 per seat / month billed yearly, $90, for 2 to 50 seats. Team + AI starts from $18.75 a seat billed yearly.
Support, refunds and cancellation
Support level rises with the plan, and the refund policy is strict.
Support channels
The plan comparison lists community support on Free, email support on Builder and priority support on higher plans. Privacy and licensing questions go to support@21st.dev.
Cancellation and refunds
You can cancel through Billing settings at any time. Cancellation stops renewals and access continues until the end of the current billing period. Payments for plans and credit packs are non-refundable, with no prorated refunds after downgrades or unused time. Upgrades apply right away and downgrades take effect at the end of the period, so start on the free plan before committing to a yearly bill.
Who should use 21st.dev
21st.dev suits React developers who want polished UI pieces delivered through their AI agent.
It fits solo builders and startups working in Next.js or Vite with Tailwind, especially those already using Claude Code, Cursor or Codex. Agencies may value Team seats with shared collections and private components. Teams that want automated design checks on pull requests can use Design Bug Bot. Developers on other frameworks, or anyone who needs refund flexibility, should look elsewhere or stay on the free plan.
Final verdict on 21st.dev
21st.dev looks like a strong source of React components for agent-driven development.
To close this 21st.dev review: the library is broad, the agent and MCP integrations are well thought out, and the entry price is low. The main cautions are the 2 copies a day limit on Free, a strict no-refund policy and SOC 2 work that is still in progress. Since Toolavero has not used it, the free plan is the safest way to test it.