Bolt.new / StackBlitz

StackBlitz builds Bolt.new, an AI application builder that lets developers, product managers, entrepreneurs and marketers create websites, prototypes and full-stack applications through conversation. Users can import Figma designs or GitHub projects and request changes in plain language. Bolt Cloud supplies hosting, custom domains, databases and authentication, bringing app creation and deployment into one interface. Teams can also build against shared design systems and collaborate within the same project.

Founded in 2017 by Eric Simons and Albert Pai, StackBlitz is led by CEO Simons and began as a browser-based development environment. Its lasting engineering contribution is WebContainers, introduced in 2021: a WebAssembly-based environment that runs Node.js, npm and development servers inside the browser sandbox. A virtual network stack mapped to Service Workers supports browser-local servers, including offline operation. This technology underpins Bolt, launched in 2024; the browser-local architecture describes its development runtime, rather than its cloud hosting.

By March 2025, Bolt.new had reached $40 million ARR, over three million registered users and more than one million monthly active users. StackBlitz raised a $105 million Series B in January 2025 at a reported $700 million post-money valuation, with Emergence Capital and GV leading the round.