PrototypeLesson 12 of 23
See Your Prototype Live
2 min readClaude Code for DesignersUpdated Feb 18, 2026
Code without a preview is just text. You'll spin up a local dev server, open localhost:3000 in your browser, and see your prototype rendered in real-time — refreshing automatically every time Claude Code makes a change.
See Your Prototype Live
Exit Claude Code
Type exit and press Enter to return to Terminal.
Initialize a React App (If Needed)
Run:
Terminal
npx create-react-app .This sets up the structure React needs to run.
Start Your Development Server
Run:
Terminal
npm startYour prototype will automatically open in your browser at localhost:3000!
Watch for Live Updates
When Claude Code makes changes, your browser automatically updates. No manual refresh needed!
Live preview running
- Set up the React project structure with create-react-app
- Started the dev server with npm start
- Confirmed the prototype renders at localhost:3000 with live reload
Two windows, one workflow. Last lesson in this module: keeping the dev server running while you keep editing.