Browserbase vs Kernel

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.

Browserbase provides managed browser sessions and TypeScript Functions that run next to a browser. Contexts preserve browser state, while its identity and secret tools address different parts of the sign-in workflow.

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.

At a glance

Sources: docs.browserbase.com [1] ↗docs.browserbase.com [2] ↗docs.browserbase.com [3] ↗docs.browserbase.com [4] ↗docs.browserbase.com [5] ↗kernel.sh [6] ↗kernel.sh [7] ↗kernel.sh [8] ↗kernel.sh [9] ↗kernel.sh [10] ↗kernel.sh [11] ↗

What survives a session

Browserbase: Contexts preserve browser data between sessions. Associate the intended Context with each user's browser and decide which sessions may update it; a Context is distinct from a live running 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.

Sources: docs.browserbase.com [1] ↗kernel.sh [2] ↗

Website login

Browserbase: The identity documentation covers website authentication and reuse of login state. Contexts and Function Secrets serve different roles: retained browser state versus values available to executing code.

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.

Sources: docs.browserbase.com [1] ↗kernel.sh [2] ↗

Where the code runs

Browserbase: A Function is TypeScript code published with an entry point. Invocation starts asynchronously, creates a browser, passes its connection URL to the handler, and stores the result, logs and session ID. Function webhooks report status changes.

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.

Sources: docs.browserbase.com [1] ↗kernel.sh [2] ↗

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.

Sources: browserarena.ai [1] ↗browserarena.ai [2] ↗github.com [3] ↗

Pricing model

Browserbase: Compare the public plan's included browser allowance and overage with the workflow's duration. Include proxy traffic and any separately priced services; an Arena browser-hour estimate does not describe the whole Browserbase bill.

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.

Sources: browserbase.com [1] ↗kernel.sh [2] ↗

Capacity and limits

Browserbase: Browser and Function constraints have separate documentation. Check the account's concurrent browser limit, the Function runtime cap and the Function region rather than assuming a browser entitlement covers every execution path.

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.

Sources: docs.browserbase.com [1] ↗kernel.sh [2] ↗

Which approach fits?

Choose Browserbase when you want to deploy TypeScript browser logic or already use Browserbase's browser and Stagehand tooling.

Browserbase tradeoff: An identity feature, a persisted Context and a Function secret solve different problems. Select the required combination instead of treating all three as automatic login.

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.

Sources: docs.browserbase.com [1] ↗kernel.sh [2] ↗

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 Browserbase and Kernel 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

Browserbase's TypeScript Function contract is a reason to retain it when that is the deployed language your team wants. A move to Notte Functions includes a Python execution decision; moving only the browser can leave your existing controller in place.

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.

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: docs.browserbase.com [1] ↗kernel.sh [2] ↗docs.notte.cc [3] ↗

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