Kitesurf
by Cloudflare
An agent-first browser that runs in V8 isolates on Cloudflare Workers
Kitesurf is Cloudflare's cloud-hosted browser built for AI agents rather than people, launched in August 2026. Written in Rust and compiled to WebAssembly, it runs inside Workers isolates instead of shipping a Chromium container, cutting the CPU and memory cost of screenshots, HTML extraction and web automation for teams running browser agents at scale.
Kitesurf is a cloud-hosted, agent-first browser that Cloudflare launched on August 6, 2026, built from scratch in Rust and compiled to WebAssembly so it runs entirely inside V8 isolates on Cloudflare Workers rather than as a containerized Chromium process. It assembles open-source components — Blitz for HTML parsing and layout, Firefox's Stylo CSS engine, the Rust-based Boa JS ECMAScript engine for eval, and Parley for text shaping — into three services: an Engine that terminates Chrome DevTools Protocol WebSocket and REST traffic and holds the only session state; PageScript, which spins up a fresh isolate with a clean globalThis and DOM document per page and iframe; and a stateless PageRenderer that emits JPEG, PNG or PDF and can be killed and relaunched without losing page state. All outbound network access is funneled through a SandboxOutbound worker that enforces CORS, injects browser-shaped headers and maintains per-page cookie isolation, on the working assumption that every page load is untrusted input. On Cloudflare's own 14-URL benchmark corpus it used 3.1–3.8x less CPU and 4.7–7x less memory than Chromium for screenshots and HTML extraction, while taking roughly 1.7–1.8x longer in wall time — an explicit trade of latency for the resources that actually drive the bill. It passes more than 215,000 Web Platform Tests and speaks CDP, so existing Puppeteer, Playwright and chrome-devtools-mcp clients connect unchanged. Cloudflare built it in twelve weeks from a first commit in May 2026 and has said it plans to open-source the engine for self-hosted deployments.
Platform and AI engineering teams already running high-volume headless-browser fleets for agents, who are paying for Chromium's CPU and memory per session and want that unit cost cut without rewriting their Puppeteer or Playwright code.
3–7x lower CPU and memory per browser task than Chromium on Cloudflare's own benchmarks, behind the same Chrome DevTools Protocol interface their existing automation already speaks.
At a Glance
- Category
- Agent Development
- Pricing
- Free, Usage-based
- Target Market
- CTOs, Enterprise Developers, Platform Engineers, AI Engineers
- Deployment
- Cloud-only, API-based
- Founded
- 2009
- Headquarters
- San Francisco, United States
- Team Size
- 500+
Key Features
- ✓Runs in V8 isolates on Workers
No container or VM per session, so cold starts and per-session memory overhead are far lower than a Chromium fleet.
- ✓Chrome DevTools Protocol compatibility
Puppeteer, Playwright and chrome-remote-interface connect by adding browser=kitesurf, so existing automation code needs no rewrite.
- ✓Per-page isolation and sandboxed egress
Each page gets a fresh isolate and clean globalThis, and all outbound traffic passes a SandboxOutbound worker enforcing CORS and cookie isolation.
- ✓Stateless disposable renderer
PageRenderer holds no state and can be killed and retried without losing page context, so a render failure degrades to a blank frame rather than crashing the session.
- ✓Quick Actions REST API
Single-call screenshot, PDF and HTML-extraction endpoints avoid writing driver code for the most common agent browsing tasks.
- ✓MCP client support
Works with Claude and other Model Context Protocol clients through chrome-devtools-mcp, so agents can drive it without a custom tool wrapper.
- ✓215,000+ Web Platform Tests passing
Published conformance coverage across CSS, DOM, HTML, SVG and XHR gives a measurable read on what will actually render.
Capabilities
Use Cases
- •Agent web research at scale
An agent fleet extracts HTML from thousands of pages per hour, and the 3.8x CPU reduction directly cuts the compute line item.
- •Automated form filling and task completion
Agents navigate and submit web forms via Puppeteer over CDP without the team operating any browser infrastructure of its own.
- •Document and report rendering
Server-side PDF and image generation from HTML templates using the Quick Actions API, billed as serverless rather than reserved capacity.
- •Untrusted page inspection
Security or compliance tooling opens suspicious URLs inside disposable isolates with controlled egress instead of on a shared automation host.
- •Cost reduction on an existing Chromium fleet
Teams route the screenshot and extraction share of their traffic to Kitesurf while leaving video, WebGL and authenticated sessions on Chromium.
Ideal For
Best For
- ✓High-volume screenshot and PDF generation from agent workflows where per-session compute cost dominates the bill
- ✓HTML and DOM extraction pipelines feeding LLM context windows, where token and compute efficiency matter more than pixel fidelity
- ✓Teams already on Cloudflare Workers who want browser automation co-located with their edge compute instead of a separate container fleet
- ✓Replacing a self-managed Chromium/Playwright cluster with a serverless endpoint that requires no capacity planning
- ✓Sandboxed browsing of untrusted pages where per-page isolation and controlled outbound networking are a security requirement
Not Ideal For
- ✗Any workflow requiring video playback or WebGL rendering — Cloudflare explicitly recommends its Chromium-backed Browser Run for these
- ✗Scraping sites behind bot challenges that negotiate on real TLS fingerprints, which Kitesurf does not reproduce
- ✗Long-running authenticated sessions that depend on persistent warm browser state, which is in direct tension with the stateless isolate model
- ✗Visual regression testing or anything needing pixel-perfect rendering or 60fps scrolling against complex web applications
- ✗Latency-sensitive interactive tasks, since wall-clock time is roughly 1.7–1.8x slower than Chromium even where CPU is far lower
Integrations
Deployment
Market Analysis
Pros
- ✓Large, independently-specified efficiency win on the two metrics that drive serverless browser cost — 3.1-3.8x CPU and 4.7-7x memory versus Chromium
- ✓No migration cost for teams already using Puppeteer or Playwright, since it speaks Chrome DevTools Protocol
- ✓Security model designed around agents reading untrusted pages, with per-page isolates and a dedicated egress-enforcing worker
- ✓Free during beta with an open-source release for self-hosting on the public roadmap
Cons
- ✗Wall-clock time is 1.7-1.8x slower than Chromium, so it trades latency for cost and is a poor fit for interactive agents
- ✗Explicitly unsupported: video, WebGL, real TLS-fingerprint bot-challenge negotiation, and long-lived authenticated sessions
- ✗Hacker News commenters flagged a conflict of interest in Cloudflare being both the dominant bot-protection vendor and a supplier of agent browsing, differentiating on which bots it blocks
- ✗Practitioners noted the isolate stops agent code escaping the sandbox but does nothing about prompt injection, since the agent still reads untrusted pages and acts on their contents
- ✗All published benchmarks are Cloudflare's own on a 14-URL corpus; no independent evaluation existed at launch
- ✗Beta-stage with undisclosed account limits and no published post-beta pricing, which makes budgeting a production migration difficult
Pricing
Beta (via Browser Run)
$0
- ✓Free while in beta
- ✓CDP endpoint access
- ✓Quick Actions API
- ✓Subject to per-account usage limits
Kitesurf is free during its beta and is accessed through Cloudflare Browser Run, subject to undisclosed per-account usage limits; Cloudflare has not published post-beta pricing, so the durable cost argument today is the 3-7x lower CPU and memory consumption versus Chromium rather than a rate card. An open-source release for self-hosting is on the public roadmap but has not shipped.
Security & Compliance
Connect
Sources
This page was written from 5 sources, 5 on domains other than kitesurf.cloudflare.app.
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