Google Stitch
Hard to argue with free: Stitch produces usable first-draft UI screens, clickable prototypes and frontend code, and since March 2026 coding agents can drive it through an MCP server and SDK. It remains a Labs experiment - usage caps, no support guarantees, and the standalone Galileo AI product it grew from was already shut down once.
Pros
- Free, with code export and handoff to AI Studio, Antigravity and Netlify
- Multimodal input: text, voice, sketches and screenshots
- MCP server and SDK let agents generate screens programmatically
- No install - runs on a Google account in the browser
Cons
- Usage caps, with no official page listing the numbers
- Experiment status means features and limits can change without notice
- Output reads like a well-made template and still needs a designer's pass