Kernel

Kernel — Fast-starting browsers plus a runtime for deploying browser agents. Kernel is two products in one: hosted browsers with persistent profiles, replays and live view, and a deployment runtime where your agent code runs next to the browser rather than calling it across the internet. The browser container images are published openly, so the thing you run in production is inspectable. Cold-start speed is the headline claim and the one nobody has independently timed. Built by Kernel (onkernel.com). Founded 2024. Seed. Open source under Apache-2.0.

We track it in 1 comparison — Browser APIs — so every claim below is a cell in a table you can open and check rather than an impression. Across those rosters it sits against 12 other tools, and what follows is where it visibly separates from them.

Where it wins.

• Session replay — Yes, which only 4 of 13 tools here manage.

Each of those is ranked against the whole roster on its category page, not against a hand-picked subset, so a first place here means first of everything we list.

Where it gives ground.

• Funding stage — seed, 8th of 13. Cloudflare Browser Rendering records public.

None of these disqualify it on their own. They are the fields to check against your own requirements before you commit, because they are the ones where a competitor genuinely does better.

Provenance. 20 of 26 tracked fields carry a value for Kernel, and 7 of those cite a document you can open. Last verified 2026-07-01. Every figure keeps its own provenance — measured by us, claimed by the vendor, inferred, or community-reported — and we would rather print a dash than a guess.

Its nearest neighbour in our data is Airtop. Kernel is ahead on Open-source core (Partial against No) and CDP endpoint (Yes against Partial). Airtop takes CAPTCHA solving (Yes against Partial) and Agent API (Yes against Partial). That pattern repeats across the rest of the roster — see Kernel alternatives for the other rivals, each compared the same way.

Company

Kernel (onkernel.com)

Founded

2024

Funding

Seed

Licence

Apache-2.0 (open source)

Fields we track

20 of 26

Last verified

2026-07-01

Interesting because it collapses the network hop: your agent runs next to the browser instead of driving it over the internet, which removes a whole class of latency and timeout bugs. The trade is that you adopt their deployment model, so it is a bigger commitment than a connection string.

Session replay

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

Stealth mode

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

CDP endpoint

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

Session persistence

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

Playwright

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

Live view

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

Puppeteer

●Yes1st of 13

Vendor-claimedverified 2026-07-01source

File downloads

●Yes1st of 13

Inferred

Kernel is the right call in these situations, each one drawn from a field we actually record:

• Latency-sensitive agent loops with chatty CDP traffic.
• Teams happy to deploy agent code onto the vendor's runtime.
• Debugging-heavy workloads that lean on replays.
• Session replay is your binding constraint. Kernel records Yes, which only 4 of the 13 tools in the Browser APIs roster do. We define that field as post-hoc recording of a finished session — video, rrweb or trace — retrievable via API or dashboard.

Reach for something else when any of the following is a requirement rather than a nice-to-have:

• Funding stage. Kernel records seed, 8th of 13 in the Browser APIs roster. Cloudflare Browser Rendering records public on the same field. If that is a hard requirement rather than a preference, start elsewhere.

We publish this block because a comparison that only lists what a tool is good at is marketing. Every figure above sits on the same page as its source, and the field definitions are on the category tables if you want to check how we measured them.

What we don't know. 6 of the 26 fields we track for Kernel are still blank: Anti-bot pass rate, Cold start, Max concurrency, Browser regions, Per browser-hour and GitHub stars. Those render as dashes rather than as zeroes or assumptions, because an empty cell and a bad cell are not the same thing and only one of them is honest. If you know any of these figures and can point at a document, tell us.