StackBlitz is a browser-based development environment that runs full-stack Node.js applications entirely within the browser using WebContainers technology — enabling instant, zero-setup coding, collaboration, and deployment. Teams use StackBlitz to create shareable live dev environments for documentation, bug reports, and onboarding without cloning repos or configuring local environments. It is the runtime that powers AI coding tools like Bolt.new and serves as the default interactive playground for documentation across major JavaScript frameworks including Angular, Vite, and StackBlitz itself.