aidenybai/react-scan

Latest recorded source activity: February 16, 2026 at 21:55

SkillsMP catalog refreshed: November 5, 2026 at 19:57

skills collected: 1

GitHub stars: 21,882
GitHub forks: 392

Install with an AI assistant

Copy this prompt into the AI assistant you're using.

Follow https://skillsmp.com/skill-install/prompt.md to install Agent Skills from https://github.com/aidenybai/react-scan.

Repository README

Repository README source: README.md

Read the source README

Expand full README

# <img src="https://github.com/aidenybai/react-scan/blob/main/.github/assets/logo.svg" width="30" height="30" align="center" /> React Scan > **You can still use React Scan, but we recommend React Doctor** > > React Doctor brings React Scan’s performance focus to coding agents, with static checks for architecture, security, accessibility, and more. [Try React Doctor →](https://react.doctor) React Scan automatically detects performance issues in your React app. - Requires no code changes -- just drop it in - Highlights exactly the components you need to optimize - Always accessible through a toolbar on page ### Quick Start ```bash npx -y react-scan@latest init ``` ### [**Try out a demo! →**](https://react-scan.million.dev) <img src="https://github.com/user-attachments/assets/c21b3afd-c7e8-458a-a760-9a027be7dc02" alt="React Scan in action" width="600" /> ## Install The `init` command will automatically detect your framework, install `react-scan` via npm, and set up your project. ```bash npx -y react-scan@latest init ``` ### Manual Installation Install the package: ```bash npm install -D react-scan ``` Then add the script tag to your app. Pick the guide for your framework: #### Script Tag Paste this before any scripts in your `index.html`: ```html  <script crossOrigin="anonymous" src="//unpkg.com/react-scan/dist/auto.global.js" ></script> ``` #### Next.js (App Router) Add this inside of your `app/layout.tsx`: ```tsx import Script from "next/script"; export default function RootLayout({ children }) { return ( <html> <head> <Script src="//unpkg.com/react-scan/dist/auto.global.js" crossOrigin="anonymous" strategy="beforeInteractive" /> </head> <body>{children}</body> </html> ); } ``` #### Next.js (Pages Router) Add this into your `pages/_document.tsx`: ```tsx import { Html, Head, Main, NextScript } from "next/document"; import Script from "next/script"; export default function Document() { return ( <Html lang="en"> <Head> <Script src="//unpkg.com/react-scan/dist/auto.global.js" crossOrigin="anonymous" strategy="beforeInteractive" /> </Head> <body> <Main /> <NextScript /> </body> </Html> ); } ``` #### Vite Example `index.html` with React Scan enabled: ```html <!doctype html> <html lang="en"> <head> <script crossOrigin="anonymous" src="//unpkg.com/react-scan/dist/auto.global.js" ></script> </head> <body> <div id="root"></div> <script type="module" src="/src/main.tsx"></script> </body> </html> ``` #### Remix Add this inside your `app/root.tsx`: ```tsx import { Links, Meta, Outlet, Scripts } from "@remix-run/react"; export default function App() { return ( <html> <head> <Meta /> <script crossOrigin="anonymous" src="//unpkg.com/react-scan/dist/auto.global.js" /> <Links /> </head> <body> <Outlet /> <Scripts /> </body> </html> ); } ``` ### Browser Extension Install the extension by following the guide [here](https://github.com/aidenybai/react-scan/blob/main/BROWSER_EXTENSION_GUIDE.md). ## API Reference <details> <summary><code>Options</code></summary> <br /> ```tsx export interface Options { /** * Enable/disable scanning * @default true */ enabled?: boolean; /** * Force React Scan to run in production (not recommended) * @default false */ dangerouslyForceRunInProduction?: boolean; /** * Log renders to the console * @default false */ log?: boolean; /** * Show toolbar bar * @default true */ showToolbar?: boolean; /** * Animation speed * @default "fast" */ animationSpeed?: "slow" | "fast" | "off"; onCommitStart?: () => void; onRender?: (fiber: Fiber, renders: Array<Render>) => void; onCommitFinish?: () => void; } ``` </details> - `scan(options: Options)`: Imperative API to start scanning - `useScan(options: Options)`: Hook API to start scanning - `setOptions(options: Options): void`: Set options at runtime - `getOptions()`: Get the current options - `onRender(Component, onRender: (fiber: Fiber, render: Render) => void)`: Hook into a specific component's renders ## Why React Scan? React can be tricky to optimize. The issue is that component props are compared by reference, not value. This is intentional -- rendering can be cheap to run. However, this makes it easy to accidentally cause unnecessary renders, making the app slow. Even production apps with hundreds of engineers can't fully optimize their apps (see [GitHub](https://github.com/aidenybai/react-scan/blob/main/.github/assets/github.mp4), [Twitter](https://github.com/aidenybai/react-scan/blob/main/.github/assets/twitter.mp4), and [Instagram](https://github.com/aidenybai/react-scan/blob/main/.github/assets/instagram.mp4)). ```jsx <ExpensiveComponent onClick={() => alert("hi")} style={{ color: "purple" }} /> ``` React Scan helps you identify these issues by automatically detecting and highlighting renders that cause performance issues. ## Resources & Contributing Want to try it out? Check the [demo](https://react-scan.million.dev). Looking to contribute? Check the [Contributing Guide](https://github.com/aidenybai/react-scan/blob/main/CONTRIBUTING.md). Want to talk to the community? Join our [Discord](https://discord.gg/X9yFbcV2rF). Find a bug? Head to our [issue tracker](https://github.com/aidenybai/react-scan/issues). [**→ Start contributing on GitHub**](https://github.com/aidenybai/react-scan/blob/main/CONTRIBUTING.md) ## Acknowledgments - [React Devtools](https://react.dev/learn/react-developer-tools) for the initial idea of highlighting renders - [Million Lint](https://million.dev) for scanning and linting approaches - [Why Did You Render?](https://github.com/welldone-software/why-did-you-render) for the concept of detecting unnecessary renders ## License React Scan is [MIT-licensed](LICENSE) open-source software by Aiden Bai, [Million Software, Inc.](https://million.dev), and [contributors](https://github.com/aidenybai/react-scan/graphs/contributors).

Loading the repository README…

Skills in this repository

Web & Digital Interface Designers

1 occupation category · 100% classified

skill

occupation

description

updated

animation-best-practices

Web & Digital Interface Designers

CSS and UI animation patterns for responsive, polished interfaces. Use when implementing hover effects, tooltips, button feedback, transitions, or fixing animation issues like flicker and shakiness.

2026-02-16

Showing 1 of 1 collected skill.