Agentic Browser Rankings

Browser Run Chromium

Cloudflare, Chromium engine, live

Cost

Chromium is Browser Run's default browser, so the published Browser Run rates apply to it directly, unlike Kitesurf which is free during beta. Workers Paid includes "10 hours per month, then $0.09 per additional hour". The free plan gives "10 minutes per day".

Limits

Converted from Cloudflare's wording: new browsers "1 every 20 seconds" free and "3 per second" paid; Quick Action requests "1 every 10 seconds" free and "30 per second" paid. Exceeding a rate returns 429. Session length is "no fixed maximum" while active, recorded as unlimited, though the free plan's 10 minutes a day caps it in practice. Sessions also close when Cloudflare deploys a new release. Paid includes 10 concurrent browsers before the $2.00 charge starts; 200 is the account ceiling. Free crawling is capped at 5 jobs a day and 100 pages each. These limits belong to Browser Run and apply to the default Chromium browser.

What it can do

The four true values come from Cloudflare's own direction on the Kitesurf page: "For these cases, use Browser Run's default browser, which is powered by Chromium." The cases are video, WebGL, bot challenges checking real TLS fingerprints, and long-running authenticated sessions. Stealth, CAPTCHA, proxies, profiles, recording and live view are never mentioned for either browser, so they stay unknown. Browser Run's overview page does not contain the word Chromium at all. Self-hosting is false: Browser Run runs only on Cloudflare.

How you connect

Terms and company

What the vendor claims

Their figures, not ours. We have not tested any of them.

• Chromium on Browser Run takes 637ms of wall time for a screenshot and 472ms for HTML extraction, using 1,173ms and 877ms of CPU and 271.0 MiB and 273.7 MiB of memory

  These are the baseline figures Cloudflare publishes for its default browser when comparing it with Kitesurf. Chromium is faster in wall time and much heavier in CPU and memory.

  How they measured it: Medians of five Quick Action runs across the 14 URL corpus at kitesurf.dev/corpus.txt, against a warm Chromium pool, which flatters its start-up time.

Sources

Browser Run Kitesurf

Cloudflare, Kitesurf engine, beta

Cost

Kitesurf is "in beta and available for free, behind per-account limits" that are not published. The pricing page never mentions Kitesurf and does not distinguish engines, so whether beta use is billed, counts toward the free 10 minutes a day, or is waived is unstated. No post-beta price is published. Chromium on the same service costs 0.09 an hour. The plan and concurrency figures recorded here are Browser Run's published rates; whether they apply to Kitesurf during beta is unconfirmed.

Limits

Converted from Cloudflare's wording: new browsers "1 every 20 seconds" free and "3 per second" paid; Quick Action requests "1 every 10 seconds" free and "30 per second" paid. Exceeding a rate returns 429. Session length is "no fixed maximum" while active, recorded as unlimited, though the free plan's 10 minutes a day caps it in practice. Sessions also close when Cloudflare deploys a new release. Paid includes 10 concurrent browsers before the $2.00 charge starts; 200 is the account ceiling. Free crawling is capped at 5 jobs a day and 100 pages each. These are Browser Run's limits; the Kitesurf page says beta use sits behind unpublished per-account limits that may differ.

What it can do

Documented limitations

• Video or WebGL rendering is not supported
• Bot-challenge handshakes with real TLS fingerprints are not supported
• Long-running authenticated sessions requiring persistent state are not supported

How you connect

Terms and company

What the vendor claims

Their figures, not ours. We have not tested any of them.

• Kitesurf passes over 235,000 Web Platform Test subtests

  By area: DOM 97%, HTML 96%, Selection 99%, SVG 97%, Encoding 99%, CORS 95%, XHR 95%, URL 83%. URL handling is the weakest by a wide margin.

  How they measured it: Not stated. The page gives counts and percentages without saying when the suite was run or against which revision of it.

• Kitesurf uses 3.1 to 3.8 times less CPU and 4.7 to 7.0 times less memory than Chromium

  Screenshot: 380ms of CPU against 1,173ms, and 57.8 MiB against 271.0 MiB. HTML extraction: 229ms against 877ms, and 39.4 MiB against 273.7 MiB.

  How they measured it: Medians of five Quick Action runs across a 14 URL corpus, published at kitesurf.dev/corpus.txt, so the test is reproducible.

• Kitesurf is 1.7 to 1.8 times slower than Chromium in wall time

  Screenshot 1,148ms against 637ms; HTML extraction 820ms against 472ms. Cloudflare publishes the figure that flatters them least. The saving is in their compute; the cost to the user is waiting.

  How they measured it: Medians of five Browser Run Quick Action runs across the same published 14 URL corpus.

Sources

Kernel

Kernel Technologies, Inc., Chromium engine, live

Cost

Rates are per second, in a table headed "Price ($/sec)" reading "Headless browser 0.0000166667". Times 3,600 that is 0.06 an hour headless, 0.48 headful, 2.88 headful with GPU. Headful is the default, so most users pay 0.48 rather than the 0.06 headline; the headline follows our cheapest-mode rule and the eight-fold gap is recorded here. Plans add a monthly fee plus credits rather than hours: Developer free with $5, Hobbyist $30 with $10, Start-Up $200 with $50. "Included monthly credits apply to usage costs only". The documentation is the price authority; the comparison page is marketing.

Limits

Concurrency is 5 on Developer, 10 on Hobbyist, 150 on Start-Up. Retention figures are for session replays: 1, 7 and 30 days by plan. Rate limits on creating browsers or on API requests are not published, and no maximum session length is documented; the timeout is set by the caller. Kernel's comparison page claims up to 72 hours on a configurable timeout, but that is marketing rather than documentation and says nothing about plans, so it is recorded as a vendor claim instead.

What it can do

Documented limitations

• The automatic CAPTCHA solver covers reCAPTCHAs, Cloudflare challenges and similar tests. hCaptcha is not included in it.
• hCaptcha solving is a separate beta feature, not enabled by default, and access must be requested from support with your use case and expected volume
• Web Bot Auth is enabled selectively on request, and only for Start-Up and Enterprise customers
• GPU-accelerated browsers do not support standby mode, so idle GPU browsers keep costing money at 2.88 an hour

Anti-detection has three layers. All browsers ship with anti-detection defaults. Stealth mode is opt-out and adds an ISP proxy plus an automatic solver for reCAPTCHAs and Cloudflare challenges, either of which can be turned off. hCaptcha is a separate beta needing a support request. Recorded as captcha_solving true, with the hCaptcha gap listed above. WebGL is true because GPU acceleration is offered explicitly for WebGL and canvas-heavy work. Video and TLS fingerprint handling are never discussed, so unknown despite this being Chromium. Self-hosting is real: kernel-images is Apache-2.0 with Docker and unikernel builds. Kernel's separate hCaptcha page now redirects into the stealth page, so both are one source. Its current wording is that the solver "is in beta and isn’t enabled for every organization by default".

How you connect

Terms and company

What the vendor claims

Their figures, not ours. We have not tested any of them.

• Kernel creates a session in 37ms against Browserbase's 213ms, 5.8 times faster

  Kernel's documentation separately claims 30ms at the median and 105ms at the 99th percentile for browser creation.

  How they measured it: browserbench, an open-source benchmark published by Steel, a competitor of both. The page states the figures are from browserbench and dates them 17 August 2026.

• A full create, connect, load and release cycle takes 794ms against Browserbase's 2,967ms, 3.7 times faster

  Measures the browser lifecycle rather than the work a real agent does.

  How they measured it: browserbench, 17 August 2026. The benchmark loads one page; it does not test whether a task succeeded.

• Sessions can run up to 72 hours on a single configurable timeout

  A product specification rather than a measurement. Not repeated in the documentation, and no statement about whether the ceiling varies by plan.

  How they measured it: Not a benchmark. Stated on Kernel's comparison page only.

Sources

Steel

Nen Labs, Inc., Chromium engine, live

Cost

Launch has no monthly fee: "$0 + usage" at "$0.10/hour". Scale is "$250 + usage" at "$0.08/hour". Launch comes with "$30 free usage credits, one time", valid 90 days, and a "$10 deposit" is required before CAPTCHA solving or Steel proxies can be enabled, counting toward usage. Steel's pages disagree on plan names: pricing lists Launch, Scale and Enterprise, while the proxies page says "Developer, Pro, & Enterprise plans" and "All plans, including Hobby (free)". The pricing page is canonical, so no free plan is recorded; the disagreement is a question for Steel.

Limits

Steel has no separate free plan, so the free and cheapest_paid columns both describe the Launch plan, which has no monthly fee and comes with one-off credits. Launch allows 10 concurrent sessions and a "15 minutes" maximum session; Scale at 250 dollars a month raises those to 100 and "1 hour", and Enterprise to "1,000+" and up to 24 hours. Rate limits on creating sessions or calling the API are not published.

What it can do

Documented limitations

• Maximum session length is 15 minutes on the entry plan, the shortest of any vendor recorded so far

Self-hosting is documented: Docker, Railway one-click deploy and clustering, source under Apache 2.0, including session management, proxies, extensions and anti-detection features. Proxies come three ways: managed residential billed per gigabyte, default datacenter addresses "Free (included in all plans)", and bring your own at "No additional costs from Steel". Persistent logins come from a Profiles API rather than long sessions. WebGL, video and TLS fingerprint handling are never discussed, so unknown.

How you connect

Terms and company

Sources