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workload / Checked 2026-10-18

Notte vs Kernel for long-running browser Functions

A handler controls a browser for an extended operation and may outlive the caller's wait timeout. Compare Notte and Kernel on the mechanism this job needs, the work that would move and a specific acceptance case.

The workflow decision

For long-running browser Functions, the useful comparison is whether Notte or Kernel can meet the following outcome: The application can determine the execution's terminal state and browser ownership after the caller stops waiting, then retrieve or cancel work through the documented path.

Handler runtime, browser lifetime and client waiting time are separate clocks. A client timeout does not necessarily cancel server-side execution or release its browser.

A proposed acceptance case

A deployed handler performs browser work longer than the caller is willing to wait. The execution must have an observable outcome even after the request ends.

This is an evaluation design, not a claim that this workflow has been executed successfully on every provider.

Part of the testRequired observation
Controlled inputA safe delayed handler, a short caller wait budget and a stored execution reference.
Pass conditionThe application can determine the execution's terminal state and browser ownership after the caller stops waiting, then retrieve or cancel work through the documented path.
Negative caseInterrupt the caller and request cancellation in a controlled test. Inspect both the handler outcome and whether its browser remains allocated.
Evidence to retainCaller timeout, execution reference, handler terminal state, cancellation result and browser release.

Documented mechanisms, side by side

These labels describe product mechanisms. The linked source and the acceptance case determine whether a mechanism meets this workflow's requirement.

RequirementNotteKernel
Code executionPython FunctionsTypeScript / Python Apps
Scheduled executionNativeApp invocation path
Recordings / replayDocumentedDocumented

Sources: docs.notte.cc [1] ↗docs.notte.cc [2] ↗kernel.sh [3] ↗kernel.sh [4] ↗

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] ↗

Deployment ownership

Notte: Use a remote browser from your existing process or deploy the browser automation as a Notte Function. These choices put lifecycle, scheduling and monitoring responsibilities in different places.

Kernel: Kernel Apps move the automation process next to the browser. Alternatively, an external process can control a browser through the browser API. Choose based on execution locality and deployment ownership.

Sources: docs.notte.cc [1] ↗kernel.sh [2] ↗

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] ↗

What should change the choice?

Notte is worth evaluating when a Python handler's run history can replace ad hoc background-job tracking. Confirm the actual runtime and cancellation contract rather than borrowing browser session limits.

Kernel: 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.

An existing worker or provider execution service may fit a long task better when its runtime and cancellation behavior are already proven. A successful browser connection is not a runtime entitlement.

Sources: docs.notte.cc [1] ↗docs.notte.cc [2] ↗notte.cc [3] ↗kernel.sh [4] ↗kernel.sh [5] ↗kernel.sh [6] ↗

The cost boundary

Use the same attempted work and eligible account capacity in both estimates. The browser-hour rate does not include every proxy, execution or identity meter, and the cost of an incomplete job is still part of the workflow budget.

The workload evidence should include: Caller timeout, execution reference, handler terminal state, cancellation result and browser release.

Sources: notte.cc [1] ↗kernel.sh [2] ↗

Make a bounded pilot

Use a safe controlled run to inspect status after the caller stops waiting, then cancel through the supported path and verify terminal cleanup.

Use the same authorized account, input and final-state check in each configuration. Treat a missing product contract as an open question; do not turn an undocumented capability into an unsupported claim or a successful test result.

  • Record source caller, handler and browser timeouts as separate budgets.
  • Port the handler without changing the business completion check.
  • Prove post-timeout status lookup, cancellation and browser cleanup before moving long jobs.

Keep comparing

Put the workflow to the test.

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