The verdict
Bolt.new collapses "prototype an app from an idea" into a single browser session — no local environment, no setup, just describe what you want and watch a working full-stack app appear. The WebContainer tech that runs Node.js in the browser is impressive and the live preview as the AI builds gives non-developers immediate feedback. For idea validation, hackathons, and weekend prototypes, Bolt is hard to beat on time-to-first-running-app. The honest critique: browser-only means no native app support, output is great for v1 demos but needs real engineering for production hardening, and credits burn fast on iteration — fixing the same bug across multiple regenerations adds up. For prototype-to-demo workflows and learning by building, Bolt fits. For production code that needs to live and evolve, IDE-tier alternatives offer more control.