5 alternatives · Checked
21st.dev is a community registry of React components, templates and shadcn themes that you drop into a project by pasting a prompt into your AI agent. It's excellent — but depending on what you're after, a single open-source library, an AI generator, or a library of real product designs might suit you better.
Written by the UIDiscovery team — we make one of the tools on this list. Competitor details come from their own websites; see sources.
The short answer
If you want free, dependable primitives, start with shadcn/ui. For animated landing-page effects, Magic UI and Aceternity UI each have strong free sets and one-time paid bundles. For generating whole screens from a prompt, v0. UIDiscovery isn't a component library at all — it's the visual reference you look at before you pick components, and it works alongside 21st.dev.
First, the incumbent
21st.dev (21st) is a community catalogue of UI built by design engineers — 12,000+ React components, templates and shadcn themes, plus shaders and gradients. Components use the shadcn registry format; you copy an AI-ready prompt into Cursor, Claude Code, v0 or Lovable, or install with the shadcn CLI. Browsing is free with 2 copies a day; Builder is $6 a month billed yearly, Builder + AI starts at $15 a month billed yearly, and Team is $7.50 per seat a month billed yearly.
Side by side
Prices in USD as listed on each site on September 22, 2026. Library sizes are each company's own figures.
Try UIDiscovery free. Browse the whole library without an account, then upgrade only if you want MCP, high-res downloads and unlimited prompts.
In detail
Best for: Free, accessible primitives you own and edit
Price: Free and open source
shadcn/ui describes itself as “not a component library” but a way to build your own: accessible components with good defaults that you copy into your codebase and edit freely, plus a CLI and a registry schema other libraries (21st.dev included) build on. It's open source and free.
Best for: Free animated components for landing pages
Price: Free components · Pro $199 one-time
Magic UI offers 150+ free, open-source animated components and effects built with React, TypeScript, Tailwind CSS and Motion. Magic UI Pro is a one-time $199 purchase that adds landing-page templates and 50+ sections with lifetime updates.
Best for: Eye-catching effects and premium landing-page blocks
Price: Free components · All-Access $169/yr or $199 one-time (sale prices when checked)
Aceternity UI is known for striking, animated components built with Next.js, React, Tailwind and Framer Motion. The free set is generous; All-Access adds 200+ premium blocks, 12+ templates and AI-ready prompts for tools like Lovable and v0, either yearly or as a one-time lifetime purchase.
Best for: Generating whole screens and apps from a prompt
Price: Free plan with $5 of monthly credits · paid plans billed per user
v0, by Vercel, generates interfaces and full apps from a prompt, with a Design Mode for visual tweaks, GitHub sync and one-click deploys to Vercel. The free plan includes $5 of credits a month; paid plans are priced per user.
Best for: Deciding what the UI should look like — before you pick components
Price: Free local preview · paid checkout is not available
UIDiscovery is the reference layer that sits in front of a component library. Browse 2,600+ real websites cut into 110,000+ sections — heroes, pricing tables, FAQs — plus 3,800+ iOS apps and 62 web apps, then send an original build prompt to v0, Lovable, Bolt, Cursor, Claude or ChatGPT, or let your agent query the library over MCP. Our Components page links out to 21st.dev so you can pick the implementation there.
Decide in a minute
Find the section you want to build, copy its prompt, and let your agent assemble it with the components you already use.
Browsing is free and you get 2 free component copies a day. When we checked on September 22, 2026, Builder was $6 a month billed yearly for unlimited copies and installs, Builder + AI started at $15 a month billed yearly with AI credits, and Team was $7.50 per seat a month billed yearly.
shadcn/ui is free and open source, and it's the base many 21st.dev components build on. Magic UI and Aceternity UI both have large free component sets if you want animated marketing sections.
No. UIDiscovery is a library of real design references — websites, sections and apps — with build prompts, tokens and MCP. Use it to decide what to build, then pick components from 21st.dev, shadcn/ui or elsewhere to implement it.
21st.dev components ship as prompts for Cursor, Claude Code, v0 and Lovable, and install via MCP or CLI. shadcn/ui's CLI works in any repo. UIDiscovery exposes an MCP server for Cursor, Claude Code and Codex, and its build prompts open in Cursor or Claude in one click.
The libraries compared here are built for React with Tailwind CSS. shadcn/ui's CLI advertises cross-framework support; check each project's docs for your framework before committing.
All competitor prices, plan details and library sizes were read from the pages below on . Prices can change and may be shown in local currency in some regions; check each site before you buy. Where a detail couldn't be confirmed on the competitor's own site, we left it out. UIDiscovery figures are counted from our library when this page is built. Product names are trademarks of their owners and are used only to identify them; this page is written by UIDiscovery and isn't affiliated with or endorsed by them.
