Making ChatGPT a true co-pilot for the web meant reimagining the entire architecture of a browser: separating Atlas from the Chromium runtime. This entailed developing a new way of integrating Chromium that allows us to deliver on our product goals: instant startup, responsiveness even as you open more tabs, and creating a strong foundation for agentic use cases.

Chromium was a natural building block. It provides a state-of-the-art web engine with a robust security model, established performance credentials, and peerless web compatibility. Furthermore, it’s developed by a global community that continuously improves it. It’s a common go-to for modern desktop web browsers.

Our talented design team had ambitious goals for our user experience, including rich animations and visual effects for features like Agent mode. This required our engineering team to leverage the most modern native frameworks for our UI (SwiftUI, AppKit and Metal), instead of simply reskinning the open source Chromium UX. As a result, Atlas’ UI is a comprehensive rebuild of the entire application UX.