v0
The strongest choice when the target stack is Next.js on Vercel, since generation, preview and deployment live in one loop and the Platform API lets you embed the whole builder. Costs are credit-metered per token, so long agentic sessions eat the included allowance fast, and output is opinionated toward Vercel's stack.
Pros
- Generates deployable full-stack code, not static mockups
- Free tier plus daily login credits support light ongoing use
- Documented Platform API and SDK for programmatic generation
- Design Mode and screenshot-to-UI shortcuts help non-coders
Cons
- Credit consumption is hard to predict on bigger builds
- Training opt-out is default only on Business and Enterprise tiers
- Output leans on Vercel deployment and ecosystem conventions