Should we build our own browser? This question has resurfaced inside Cloudflare for years, sparking long internal threads with many arguments about why we should do it. The browser is important software we use daily, arguably the operating system of the Internet, and we have repeatedly wrestled with technical difficulty versus problems we could solve.

Until now, technical advances in our Developer Platform coincided with AI agents needing a new browser. Running WebAssembly in Workers is mature, offering dynamic workers, Durable Objects, RPC, service bindings, higher Node.js compatibility and limits, enabling ambitious apps. Chromium, built for humans, consumes excessive memory and compute, making per‑agent instances prohibitive.

After 12 weeks of reconsideration, the answer was unanimous: Yes! We announce Kitesurf, a browser that runs entirely on Cloudflare Workers and is free in beta via Browser Run. Kitesurf uses far less CPU and memory than Chromium for tasks like screenshots and HTML extraction.

Design decisions include extensive testing with Web Platform Tests, curated feature assignments for AI agents, and integration plus visual regression testing on real sites. We compile native Rust to WebAssembly via wasm‑bindgen, avoid heavy emulation layers, enforce strict exception handling that degrades to blank frames, and isolate each component so every page load is untrusted and each session starts fresh. Stateless components are disposable and parallelizable.