Notte vs Kernel

The decision

Kernel Apps put TypeScript or Python code alongside the browsers they create. Notte Functions supply a Python handler, invocation and run-history layer. Kernel's execution locality is worth testing for action-heavy code; Notte's combined session, Function and authentication workflow is worth testing when those resources need to work together.

Notte combines cloud browser sessions with deployed Python automations and website authentication tools. You can control the browser over CDP or use Notte's actions, then deploy repeated work as a Function.

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.notte.cc [1] ↗docs.notte.cc [2] ↗docs.notte.cc [3] ↗docs.notte.cc [4] ↗docs.notte.cc [5] ↗docs.notte.cc [6] ↗kernel.sh [7] ↗kernel.sh [8] ↗kernel.sh [9] ↗kernel.sh [10] ↗kernel.sh [11] ↗kernel.sh [12] ↗

What survives a session

Notte: Profiles save cookies, local storage and session storage. Sessions start with fresh state by default. Persisting a profile writes state back when the session ends; a running session can also save its state explicitly.

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.notte.cc [1] ↗kernel.sh [2] ↗

Website login

Notte: Vaults substitute credential placeholders in supported browser actions outside the model context. Managed Auth checks requested saved connections before automation. Personas supply an inbox and optional phone number for verification workflows.

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.notte.cc [1] ↗kernel.sh [2] ↗

Where the code runs

Notte: Functions deploy Python code with a run() entry point. Invoke them over HTTP or with an SDK, inspect run history, and roll back code by redeploying an earlier version as the latest version.

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.notte.cc [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

Notte: The public usage rates are $0.01 per browser-hour, $0.05 per Function-hour and $10 per GB of managed proxy traffic. Paid plans return their price as usage credits. Price the relevant meters and plan eligibility for the workload.

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: notte.cc [1] ↗kernel.sh [2] ↗

Capacity and limits

Notte: The public plans list 5, 25 and 100 concurrent browser sessions, with custom limits on Enterprise. Session duration and concurrent capacity are separate plan limits; a larger technical API limit does not override the plan.

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: notte.cc [1] ↗kernel.sh [2] ↗

Which approach fits?

Choose Notte when your browser workflow needs saved logins, credential fill or scheduled Python code alongside the browser.

Notte tradeoff: A saved profile restores browser state; it does not prove that a website still considers the user signed in. Use Managed Auth when the workflow needs connection readiness before it starts.

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.notte.cc [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 Notte 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.

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