The decision
Start with the product contracts for saved browser state, credential handling, website sign-in, code execution. Different labels do not establish different functionality; compare the implementation and conditions behind each one.
Kernel provides cloud browsers and an app platform for TypeScript or Python code. App actions run alongside Kernel browsers, while profiles and Managed Auth handle retained state and sign-in connections.
Cloudflare Browser Run provides headless browser sessions through CDP and browser code deployed in Workers. This comparison concerns sessions and their execution model, rather than the separate Quick Actions APIs.
At a glance
| Requirement | Kernel | Cloudflare Browser Run |
|---|---|---|
| Browser control | Documented | Documented |
| Saved browser state | Documented | Session reuse / custom state |
| Credential handling | Vaults (preview) | Application-owned |
| Website sign-in | Documented | Not established |
| Code execution | TypeScript / Python Apps | Workers composition |
| Scheduled execution | App invocation path | Workers trigger composition |
| Live view | Documented | Beta |
| Recordings / replay | Documented | Beta |
| Deployment choice | Check deployment offering | Cloudflare service |
Sources: kernel.sh [1] ↗kernel.sh [2] ↗kernel.sh [3] ↗kernel.sh [4] ↗kernel.sh [5] ↗kernel.sh [6] ↗developers.cloudflare.com [7] ↗
What survives a session
Kernel: Profiles preserve browser user-data-directory state, including cookies, site data, tabs and preferences. Profile sharing and save behavior need explicit treatment when parallel workers use seeded state.
Cloudflare Browser Run: Cloudflare documents reuse of browser sessions and a Durable Objects integration. Keeping a session alive is different from exporting a portable authenticated profile; design the required state store explicitly.
Website login
Kernel: Managed Auth handles website login and eligible connection recovery. Vault fill is a separate flow for applications that control navigation and form submission; the reviewed vault documentation labels that surface as preview.
Cloudflare Browser Run: Use browser code to implement the website's sign-in flow and retain the necessary session state. The reviewed overview does not establish a managed website connection that checks sign-in readiness before a workflow starts.
Where the code runs
Kernel: Deploy a TypeScript or Python App and expose Actions that callers invoke. Kernel co-locates code with the browser environments the app creates. An Action invocation is the execution unit rather than a bare CDP connection.
Cloudflare Browser Run: Deploy browser automation within a Cloudflare Worker or connect to Browser Run from an external process over CDP. Workers provide the execution layer; compare their runtime and deployment model separately from browser access.
Published browser measurements
These are the latest provider runs in the saved BrowserArena snapshot checked on October 18, 2026. Dates and runner environments can differ. A lifecycle test opens, connects, navigates and releases a browser; the throughput test runs a separate browser action sequence. Neither measures managed authentication or deployed Function reliability.
Use these observations to choose what to test in your application. An account-configuration failure, an incompatible page action and a timed-out navigation require different interpretations. BrowserArena is maintained by Notte and publishes its source and methodology.
| Provider | Lifecycle median | Lifecycle P95 | Actions / second | Run dates |
|---|---|---|---|---|
| Kernel | 334 ms | 700 ms | 3.32 | 2026-10-18 / 2026-10-17 |
| Cloudflare Browser Run | 769 ms | 1339 ms | 2.73 | 2026-10-18 / 2026-10-17 |
Sources: browserarena.ai [1] ↗browserarena.ai [2] ↗github.com [3] ↗
Pricing model
Kernel: Use the plan and browser configuration in Kernel's pricing documentation. Managed networking, account allowances and app execution make a browser-hour comparison only one part of the decision.
Cloudflare Browser Run: Price browser usage and the Worker execution components required by the workload. The Browser Run pricing page, rather than a single browser-hour estimate, defines included allowances and applicable limits.
Capacity and limits
Kernel: Kernel documents concurrent browsers, browser creation rate and per-browser resources separately. Standby browsers can still consume concurrency. Pools change how browsers are acquired; they do not erase account limits.
Cloudflare Browser Run: Browser Run has its own limits and pricing alongside Workers. Account browser capacity, session creation limits and the Worker execution budget constrain different parts of a workflow.
Which approach fits?
Choose Kernel when your code makes many browser calls and you want to deploy it beside the browser, or you need Kernel's managed sign-in flow.
Kernel tradeoff: Browser-local code changes the deployment model. Check app action behavior, account limits and persistent-state ownership before moving an external worker into it.
Choose Cloudflare Browser Run when you already deploy Workers and want browser automation within that application's execution and scheduling model.
Cloudflare Browser Run tradeoff: A Worker and a browser session have separate resource and lifecycle constraints. Confirm the chosen browser library and binding path instead of assuming an unchanged local browser script will deploy directly.
Check the browser connection
Install playwright-core in your application and provision a session through the provider's documented creation flow. Run this smoke test from the intended controller region with the returned CDP endpoint. It checks connection and navigation, not login, rendering parity or a complete business workflow.
Keep browser connection URLs on your backend. After the test, release the owned session through the provider's API. Product-specific lifecycle APIs and profile identifiers are not portable between providers.
import { chromium } from "playwright-core";
// Provision the owned browser using the provider's documented session API.
// Keep the connection URL in your backend's secret environment.
const endpoint = process.env.BROWSER_CDP_URL;
if (!endpoint) throw new Error("Set BROWSER_CDP_URL for an owned session");
const browser = await chromium.connectOverCDP(endpoint);
try {
const context = browser.contexts()[0] ?? await browser.newContext();
const page = context.pages()[0] ?? await context.newPage();
await page.goto("https://example.com", { waitUntil: "domcontentloaded" });
if ((await page.title()) !== "Example Domain") {
throw new Error("The browser did not reach the expected page");
}
console.log({ connected: true, expectedPage: true });
} finally {
await browser.close();
// Release the owned session with the provider's documented API as well.
// A disconnected socket alone is not a portable session-cleanup contract.
}Sources: playwright.dev ↗
Before you switch
Keep the same target workflow when evaluating both products. Separate infrastructure facts from measurements and test the required account state, action sequence and artifacts. A successful connection test does not establish that a long or authenticated task will complete.
Use the focused guides for Kernel and Cloudflare Browser Run below when the deciding requirement is pricing, persistence or code execution. Provider-owned resources such as session IDs, profiles and managed connections need a new mapping during migration.
When Notte belongs on this shortlist
Kernel's browser-local Apps make execution placement part of the decision. Compare the repeated action path with the proposed Notte controller or Function deployment before concluding that a lifecycle or hourly-rate difference decides the workflow.
Cloudflare can be an economical architectural choice when Workers and the surrounding scheduling already exist in your application. Notte is worth evaluating when a browser, deployed Python handler and authentication workflow should share a product rather than a Workers composition.
Notte: Create an owned browser session, connect Playwright or Puppeteer over CDP, and stop the session when the work finishes. Browser lifecycle management remains necessary even when the control socket disconnects.
Consider this third option when its documented mechanism addresses a requirement left open by the two providers above. A working configuration on either original provider can still be the better choice; compare the task and ownership cost before switching.
Sources: kernel.sh [1] ↗developers.cloudflare.com [2] ↗docs.notte.cc [3] ↗