Kernel vs Browserless

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.

Browserless provides hosted browser access and self-hosted options. Its documentation separates BaaS, BrowserQL and BAP, with different ways to control sessions, preserve state and use credentials.

At a glance

Sources: kernel.sh [1] ↗kernel.sh [2] ↗kernel.sh [3] ↗kernel.sh [4] ↗kernel.sh [5] ↗kernel.sh [6] ↗docs.browserless.io [7] ↗docs.browserless.io [8] ↗docs.browserless.io [9] ↗docs.browserless.io [10] ↗docs.browserless.io [11] ↗docs.browserless.io [12] ↗

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.

Browserless: Browserless documents authenticated profiles and reconnect flows. A retained profile and a reconnectable live browser preserve different state; choose the mechanism based on whether the running page must continue.

Sources: kernel.sh [1] ↗docs.browserless.io [2] ↗

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.

Browserless: BAP documents loadSecret() with a configured 1Password integration. Profiles provide another way to reuse authenticated state. Check the selected product's prerequisites before treating these as interchangeable login options.

Sources: kernel.sh [1] ↗docs.browserless.io [2] ↗

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.

Browserless: Browserless supports several code and control surfaces. Compare the exact runtime endpoint or external runner you intend to use, including its language, deployment, versioning and invocation contract.

Sources: kernel.sh [1] ↗docs.browserless.io [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

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.

Browserless: Browserless Cloud uses units. Browser time consumes one unit per 30-second increment, rounding partial increments upward; proxy traffic and other services also consume units. Included units and overage depend on the plan.

Sources: kernel.sh [1] ↗docs.browserless.io [2] ↗

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.

Browserless: Account concurrency and session routing affect a Browserless deployment. Use its concurrent-session guidance, and distinguish shared cloud, managed dedicated and self-hosted capacity.

Sources: kernel.sh [1] ↗docs.browserless.io [2] ↗

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 Browserless when you need a browser service that fits existing automation libraries or a self-hosted deployment, and can select the appropriate Browserless product.

Browserless tradeoff: The connection route and product matter. A feature documented for BAP or a managed dedicated deployment should not be assumed to exist on every shared BaaS endpoint.

Sources: kernel.sh [1] ↗docs.browserless.io [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 Kernel and Browserless 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.

Choose the Browserless product and deployment before drawing a conclusion from its documentation. BAP, shared browser access and a self-hosted service can have different features; Notte's session and Function resources should be compared with the specific path you would purchase.

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] ↗docs.browserless.io [2] ↗docs.notte.cc [3] ↗

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