Handle

Handle, made by Tonkotsu AI, enables designers and developers to design directly in production code, providing live visual tools to modify UI elements, styling, and layout in web apps, with changes automatically synced back to the codebase. It offers a Chrome extension for visual refinement directly within the browser, a macOS desktop app called Handle Studio for dedicated design work, and integration with multiple coding agents including Claude Code, Cursor, GitHub Copilot, and Gemini CLI. Handle provides live preview with real-time code synchronization and element selection and styling adjustment tools, letting users point at UI elements and fix them directly rather than repeatedly re-prompting an AI coding agent. Handle is completely free and open source, available on GitHub, with no account required; users bring their own coding agents to power the underlying changes.