Cloudflare said on November 13, 2026 that the source for Kitesurf, its experimental browser engine for AI agents, is on GitHub under the Apache 2.0 license. In a Cloudflare Blog post dated November 13, 2026, the company wrote: "Kitesurf is open source on GitHub under the Apache 2.0 license." The repository says: "Kitesurf is an experimental browser engine that runs on Cloudflare Workers." A Workers Paid plan is required to run the engine on Cloudflare.

#What changed?

Cloudflare's November 13, 2026 post says: "You can read the code, run it locally, change it, and deploy your own instance to Cloudflare Workers." That instance runs on the developer's own Cloudflare account.

The repository says: "It parses HTML, applies CSS, runs page JavaScript, and renders screenshots without Chrome or a browser container." The post says: "Kitesurf runs entirely on Cloudflare Workers." It supports the Chrome DevTools Protocol (CDP), so clients such as Puppeteer can connect. Cloudflare's post also calls it "our stateless browser for AI agents that runs entirely on top of Workers".

Cloudflare wrote: "Our main goal is to give AI agents a lightweight, efficient browser". The same sentence describes that goal as "while using less CPU and memory than a full browser like Chromium, and scaling on demand across Cloudflare’s global Workers network."

The post says Kitesurf builds on Rust packages compiled to WebAssembly. Blitz provides HTML parsing, the DOM, layout, and painting. Stylo provides CSS parsing, cascading, and computed styles. Boa "runs JavaScript inside WebAssembly (as the last resort only when we can’t run JavaScript in Dynamic Workers)." Linebender libraries provide text layout and 2D graphics, and Krilla generates PDF output. Cloudflare wrote: "Kitesurf has three main parts: the Engine manages browser sessions and client connections, PageScript runs the page and its JavaScript, and PageRenderer draws the result." The README says bundled fonts, data, and dependencies keep their own licenses.

Cloudflare introduced Kitesurf in an August 6, 2026 post. A September 28, 2026 update followed. The November 13 post says that September follow-up added WebMCP support, new APIs, and improved compatibility. Phoronix, in a report by Michael Larabel dated November 13, 2026, also covered the GitHub publication.

#Who can use it and when?

A self-deployed copy of Kitesurf runs on the developer's own Cloudflare account under a Workers Paid plan, and in Cloudflare's managed Browser Run service Kitesurf is a free beta option with Chromium as the default. Developers can run the code locally and, according to Cloudflare, deploy the engine to their own account and use that copy instead of the Browser Run managed APIs. The repository states: "A Cloudflare Workers Paid plan is required to run Kitesurf on Cloudflare." The November 13 post says the paid plan is required because Kitesurf uses Dynamic Workers to create isolated Workers for pages.

Cloudflare's Browser Run docs, last updated November 13, 2026, say "Kitesurf is in beta and available for free, behind per-account limits". On that managed service, Kitesurf is an option, not the default. The same page says the Browser Run CDP endpoint supports Kitesurf as an option, so existing Puppeteer, Playwright, or chrome-remote-interface setups already work. For cases Kitesurf cannot handle, the docs say: "For these cases, use Browser Run's default browser, which is powered by Chromium."

#What are the limits?

Cloudflare's documentation says Kitesurf cannot play video or render WebGL, cannot negotiate a bot-challenge handshake with real TLS fingerprints, and cannot start a long-running authenticated session that requires persistent state. The repository calls the engine experimental. The November 13 post says Kitesurf is under heavy development, with work focused on making the engine more compatible, more reliable, and more efficient. The README also says: "Kitesurf provides a CDP endpoint, not a full Chrome implementation." "Some Chrome DevTools features do not work yet."

The same README warns: "Do not deploy Kitesurf without authentication in front of it." It also says the engine has no authentication of its own. Anyone who has the URL of an unprotected deployment can browse the web through the engine, send outbound requests that come from the owner's Cloudflare account, and use CPU time and Dynamic Workers that the account pays for. Cloudflare tells operators to put Cloudflare Access, or another login layer, in front of a deployment.

Cloudflare's own performance figures, in the Browser Run docs last updated November 13, 2026, are the company's tests, not independent results. The docs say: "It uses less CPU and memory than Chromium for common agentic tasks, at the cost of slightly slower wall time and rendering that is not pixel-perfect." The figures are the medians of five Browser Run Quick Action runs across a 14-URL corpus, comparing Kitesurf with Chromium in a warm pool.

Metric

Kitesurf

Chromium (warm pool)

Cloudflare's comparison

CPU, screenshot

380 ms

1,173 ms

3.1 times less CPU than Chromium

CPU, HTML extraction

229 ms

877 ms

3.8 times less than Chromium

Memory, screenshot

57.8 MiB

271.0 MiB

4.7 times less than Chromium

Memory, HTML extraction

39.4 MiB

273.7 MiB

7.0 times less than Chromium

Wall time, screenshot

1,148 ms

637 ms

1.8 times slower than Chromium

Wall time, HTML extraction

820 ms

472 ms

1.7 times slower than Chromium

The same docs say: "These numbers are a snapshot and improve over time." On Web Platform Tests (WPT), Cloudflare writes "As of the latest run, Kitesurf passes over 235,000 subtests". It also says: "WPT measures conformance to web standards, not a browser's ability to render and interact with every real-world website."

#How does it compare?

Kitesurf is a Cloudflare Workers browser engine that agents can control through the Chrome DevTools Protocol, and a self-deployed copy runs on the developer's own Cloudflare account, unlike agent stacks that run in a customer's own cloud or on a local machine. GPT-6.1 Terra is OpenAI's model for computer use, including agents that drive browsers and screens. Self-hosted Claude Managed Agents is a private beta in which customers run Anthropic's agent service in their own cloud or on-premise, unlike a self-deployed Kitesurf instance, which runs on the developer's Cloudflare account. The Agentic AI Foundation's Agent Skills, Open Responses, OpenEnv and OpenSandbox projects are agent infrastructure components that vendors have donated to the foundation. Perplexity Computer can run fully locally on Apple silicon Macs.

Our analysis: Publishing Kitesurf under the Apache 2.0 license lets developers read the code, change it, and run a copy, but that copy still depends on Cloudflare Workers and a Workers Paid plan. The managed Browser Run path is separate: Chromium stays the default, and Kitesurf is a free beta option with per-account limits. Teams that need video, WebGL, bot-challenge handshakes, or long logged-in sessions are still pointed at a full Chromium browser. An unprotected deployment is also a practical risk, because the engine has no authentication of its own.