Source: https://seerepo.com/compare/shadcn-ui/ui/vs/stenciljs/core
Markdown source: https://seerepo.com/compare/shadcn-ui/ui/vs/stenciljs/core.md
Description: ui and core share 3 technologies: PostCSS, prompts, and postcss-selector-parser. Both are written in TypeScript.

# ui vs core

ui and core share 3 technologies: PostCSS, prompts, and postcss-selector-parser. Both are written in TypeScript.

- [shadcn-ui/ui](https://seerepo.com/r/shadcn-ui/ui): Composable, accessible components with thoughtful defaults. Build your own component library with code you can customize, extend, and make your own.
- [stenciljs/core](https://seerepo.com/r/stenciljs/core): A toolchain for building scalable, enterprise-ready component systems on top of TypeScript and Web Component standards. Stencil components can be distributed natively to React, Angular, Vue, (+ more) and traditional web applications from a single, framework-agnostic codebase.

## What they share and what sets them apart

- In common: PostCSS, prompts, postcss-selector-parser
- Only in ui: Next.js, React, fumadocs-core, lru-cache, Vercel, SQLite, MCP, React Router, Vite, TanStack, Tailwind CSS, cn, class-variance-authority, next-themes, recharts, Radix UI, Base UI, react-aria-components, sonner, react-resizable-panels, embla-carousel-react, input-otp, react-day-picker, cmdk, dnd-kit, motion, vaul, React Hook Form, Lucide, hugeicons, @tabler/icons-react, @phosphor-icons/react, @remixicon/react, ai, @ai-sdk/react, shiki, react-qr-code, streamdown, front-matter, unist-util-visit, Zod, ora
- Only in core: Autoprefixer, css-what, postcss-safe-parser, parse5, pixelmatch

## Side by side

| | ui | core |
|---|---|---|
| Size | 636,360 lines written, 3,888 code files | 180,037 lines written, 595 code files |
| Who writes it | 2.9% of its commits signed by AI. With Claude Code, Cursor, GitHub Copilot, Codex, and Devin | 0% of its commits signed by AI. With GitHub Copilot and Claude Code |
| Activity | Last push November 8, 2026, 2,308 commits, 127,657 stars | Last push November 9, 2026, 8,382 commits, 13,153 stars |
| Tests | 415 test files. 3.8% of its code files have a test that imports them | 1,020 test files. 33.9% of its code files have a test that imports them |

- Size: Lines written by people and agents, without generated ones; code files, without tests.
- Who writes it: A commit counts as AI's when it carries its signature: a Co-Authored-By line, its author name or the merge of its branch.
- Activity: From GitHub and its history, on the day SeeRepo read it.
- Tests: The files that test the code, and the share of code files a test imports.

## Frequently asked questions

### Which is bigger, ui or core?

ui, with 636,360 lines written; core has 180,037.

The proof: [shadcn-ui/ui's code at commit 8ab2771](https://github.com/shadcn-ui/ui/tree/8ab27715521cbd4f87ae6886cd989cbb678f6de7)

### Which has more GitHub stars, ui or core?

ui, with 127,657 stars; core has 13,153.

The proof: [shadcn-ui/ui on GitHub](https://github.com/shadcn-ui/ui)

### Which has more tests, ui or core?

core, with 1,020 test files; ui has 415.

The proof: [stenciljs/core's code at commit bb880de](https://github.com/stenciljs/core/tree/bb880de3cf2f4428903ecbbd875f4b9cf37d5ce6)

### Which was updated more recently, ui or core?

core: its last push was on November 9, 2026, and ui's on November 8, 2026.

The proof: [stenciljs/core's commits on GitHub](https://github.com/stenciljs/core/commits)

### Which has more commits signed by AI, ui or core?

ui: an AI signed 2.9% of its commits, with Claude Code, Cursor, GitHub Copilot, Codex, and Devin.

The proof: [the commits each tool signed in shadcn-ui/ui](https://seerepo.com/r/shadcn-ui/ui/ai)

## Sources

- shadcn-ui/ui: Read on November 9, 2026, at commit 8ab2771 (https://github.com/shadcn-ui/ui/tree/8ab27715521cbd4f87ae6886cd989cbb678f6de7)
- stenciljs/core: Read on November 10, 2026, at commit bb880de (https://github.com/stenciljs/core/tree/bb880de3cf2f4428903ecbbd875f4b9cf37d5ce6)

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.