AI code-based site builders generate real, deployable code — usually React + Tailwind, often with a backend, auth and a database — from a natural language brief. They are aimed at users who want to own the codebase, deploy on their own infrastructure, and break out of the constraints of a closed builder.
Lovable, Bolt.new, v0 by Vercel and Replit Agent are the leaders. They differ on how 'agentic' they are (does it run, deploy and self-correct or just generate code?), what frameworks they support, how the chat-edit loop is wired, and whether they include hosting and a backend out of the box. For developers, AI-native editors like Cursor accelerate the same workflow inside an existing repo.