boat vs Kernel

Kernel is browser infrastructure: it hands your agent a Chromium browser on a small unikernel and deletes it when the session ends. boat hands your agent a whole Linux VM with Docker, a disk that persists, a 60fps desktop with Chromium and coding agents built in.

Where boat stands out

A whole machine, not only a browser

A boat sandbox is a full Linux VM with root, systemd, Docker and /dev/kvm, 4 vCPU / 8 GB by default and up to 16 vCPU / 32 GB. A Kernel browser is a single-purpose unikernel built to run Chromium, with 1 to 16 GB of memory and no published vCPU count. You can run commands in it, but Kernel's docs suggest uploading a binary for custom software.

Files that stay, and a fork of a running sandbox

boat keeps the disk, snapshots it every minute and on stop, and a stopped sandbox costs nothing. You can fork a running sandbox into a copy to try two paths at once. A Kernel browser is deleted after its timeout, and only cookies, storage and browser state carry over in a profile.

Coding agents and a key proxy built in

boat ships Claude Code, Codex, OpenCode and other agents inside each sandbox, and you drive them from outside with a prompt, steer and events API. boat's credentials proxy keeps real API keys outside the sandbox for model providers and any HTTPS API you register. Kernel's vaults fill logins into the page, and its docs say page scripts can read them after that.

The companies and products

boat

boat.dev runs sandboxes for AI agents: each one is a full Linux VM with its own kernel.

You start a machine with one command or one API call, then SSH in, run Docker, open a desktop, or let a built-in agent (Claude Code, Codex, OpenCode and others) work in it. The disk stays between sessions, and a stopped sandbox costs nothing.

Isolation: Full VM per sandbox, own kernel
Hardware: Dedicated AMD Ryzen 9 9950X (Zen 5) hosts
Regions: EU: Germany, Finland, France
Plans: From $20 a month, all of it usage credit, 7-day trial

Kernel

Kernel is browser infrastructure for web agents and automations: you create cloud Chromium browsers from its API and drive them over CDP.

Each Kernel browser is Chromium on its own Unikraft-based unikernel, headless (1 GB) or headful (8 or 16 GB) with Live View and a computer controls API. Around it Kernel sells stealth mode with proxies and a CAPTCHA solver, saved browser profiles, managed logins, session replays and an app runtime for your agent code. It is a different kind of product from boat: a managed browser, not a general sandbox, so this page compares where the two overlap, which is agents that use a browser.

Company: Kernel Technologies, Inc., a Delaware corporation
Isolation: Each browser runs on a dedicated Unikraft-based unikernel; cold starts under 20 ms
Browser memory: 1 GB headless; 8 GB headful, or 16 GB when set on create; vCPU count not published
Regions: us-east, eu-west and ap-southeast; choosing a region needs the Start-Up or Enterprise plan
Concurrency: 5, 10 and 150 browsers on Developer, Hobbyist and Start-Up; custom on Enterprise
Billing: $0.0000166667 per GB-second while active; no charge for standby or proxies
Compliance: The Enterprise plan lists SOC 2 and HIPAA compliance
Source code: Browser images are public on GitHub (kernel-images)

Which use cases each one fits

For each use case, Battleships prices every sandbox provider on the same workload and sorts them from the cheapest monthly bill up. “3rd cheapest of 367” means 2 of the other 366 providers run that workload, with every feature it needs, for less. “With limits” means the provider runs it but misses something, so it is listed after every full match. Open a use case for its whole ranking and what each provider misses.

Use case and its workload	boat: price rank	Kernel: price rank
Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Kernel is a compromise here: its browser VM keeps no disk and documents no Docker, so installs, builds and tests belong on a machine like boat's.	3rd cheapest of 367 $634 a month	98th of 367, with limits $873 a month
Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An assistant that works all month needs files that stay; a Kernel browser's files go when it is deleted, and only cookies and storage live on in a profile.	5th cheapest of 366 $657 a month	203rd of 366, with limits $2,033 a month
Code interpreter bursts 100 at once · 1 vCPU / 2 GB · 200,000 sessions of 1 min a month	186th of 345, with limits $2,000 a month	266th of 345, with limits $347 a month
Sandboxes for your users 300 at once · 2 vCPU / 4 GB · 30,000 sessions of 23 min a month 300 sandboxes at once is more than Kernel's Start-Up limit of 150 browsers, and each user gets a browser rather than a machine.	Cheapest of 361 $209 a month	228th of 361, with limits $768 a month
RL rollouts 1,000 at once · 2 vCPU / 4 GB · 1,000,000 sessions of 3 min a month	34th of 360, with limits $2,000 a month	246th of 360, with limits $3,133 a month
Agent evals 250 at once · 4 vCPU / 8 GB · 15,000 sessions of 20 min a month	10th cheapest of 364 $200 a month	252nd of 364, with limits $390 a month
CI runners 40 at once · 8 vCPU / 16 GB · 6,000 sessions of 12 min a month CI needs Docker and a known CPU size; Kernel documents neither, so it is a compromise.	4th cheapest of 377 $86 a month	259th of 377, with limits $222 a month
24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB	18th cheapest of 368 $26 a month	144th of 368, with limits $33 a month
Computer-use agents 50 at once · 4 vCPU / 8 GB · 20,000 sessions of 15 min a month Both fit: Kernel has Live View and a computer controls API for its browser, and boat streams a 60fps desktop where the agent can use any Linux app, not only the browser.	6th cheapest of 369 $200 a month	38th cheapest of 369 $1,878 a month
Browser-use agents 50 at once · 2 vCPU / 4 GB · 30,000 sessions of 10 min a month Both fit: Kernel gives a browser over CDP with stealth built in, and boat gives a Chromium on a full VM where the agent can also run code.	7th cheapest of 367 $200 a month	21st cheapest of 367 $366 a month
Scraping & bots (startup scale) 50 at once · 1 vCPU / 2 GB · 100,000 sessions of 3 min a month	6th cheapest of 346 $90 a month	45th cheapest of 346 $443 a month
Mass scraping & bots (undetectable) 1,000 at once · 1 vCPU / 2 GB · 3,000,000 sessions of 2 min a month Kernel fits mass scraping better: stealth mode, ISP and residential proxies and a CAPTCHA solver come with the plan, while boat uses datacenter IPs and solves no CAPTCHAs.	71st of 338, with limits $1,800 a month	4th of 338, with limits $6,000 a month
Parallel red teaming 200 at once · 2 vCPU / 4 GB · 5,000 sessions of 30 min a month	2nd cheapest of 360 $200 a month	61st of 360, with limits $293 a month
GPU eval jobs 10 at once · 8 vCPU / 32 GB · 500 sessions of 30 min a month	Can't run it	Can't run it
macOS agents 5 at once · 4 vCPU / 8 GB · 1,000 sessions of 20 min a month	Can't run it	Can't run it

Key features

Feature	boat	Kernel
Kind of product	A full Linux VM per sandbox, with a desktop and Chromium inside	A managed Chromium browser per session, with an app runtime for your code
Isolation	Every sandbox is a full VM with its own kernel	Every browser runs on its own Unikraft-based unikernel; root inside has no path to other customers
Machine size	4 vCPU / 8 GB by default, up to 16 vCPU / 32 GB by plan	1 GB headless, 8 or 16 GB headful; vCPU count not published
Docker and nested virtualization	Docker, systemd and /dev/kvm on every machine	A single-purpose unikernel; no container runtime or /dev/kvm documented
Shell access	SSH and root on every machine	SSH into the browser VM, and process exec with an as_root option
Files after a session	The disk persists, with snapshots every minute and on stop; a stopped sandbox costs nothing	The browser is deleted after its timeout; profiles keep cookies, storage and browser state, not files
Idle and wake	Stop and resume by API; resume reboots from disk (no memory snapshots)	Standby after 5 seconds idle with a memory snapshot and zero usage charge; a new connection picks it up
Fork	Fork a running sandbox into a copy	No fork; browser pools keep fresh browsers warm
Browser and computer use	60fps desktop and Chromium, computer use and browser control, embeddable stream	Headful Chromium with Live View, a computer controls API, CDP and session replays
Bot detection	Datacenter IPs and Chromium; no CAPTCHA solving	Stealth mode with an ISP proxy and a CAPTCHA solver; residential proxies; proxies not charged
Reaching the machine	HTTPS URLs for up to 50 ports, token-protected; raw TCP; dedicated IPv6 or IPv4	No inbound ports; tokenized CDP and Live View URLs, and SSH port forwarding
Keeping keys out of the sandbox	AI credentials proxy for model providers and any HTTPS API you register; switch a credential to another account when credits run out	Vaults fill logins into forms, where page scripts can read them; managed auth keeps sign-ins in profiles
Coding agents	Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API	A Claude Agent SDK app template that installs Claude Code when you deploy your app
Regions	EU only: Germany, Finland, France	us-east, eu-west and ap-southeast; region choice from the Start-Up plan
Compliance and transparency	SOC 2 is in progress. We're open about where we stand: live status and data retention policy.	SOC 2

Every feature Battleships tracks (43)

Feature	boat	Kernel
Full VM (own kernel)	Yes	Yes
Docker inside	Yes	No
Nested virtualization	Yes	No
Root	Yes	Yes
Systemd	Yes	Not published
Desktop GUI	Yes	Yes
Browser	Yes	Yes
Computer-use API	Yes	Yes
SSH	Yes	Yes
Persistent disk	Yes	No
Pause/resume	Yes	Yes
Automatic snapshots	Yes	Yes
Fork/clone	Yes	No
Live fork (no pause)	Yes	No
Memory fork	No	No
Custom image (Docker or snapshot)	Yes	Yes
≥24 h sessions	Yes	Yes
Idle auto-stop	No	Yes
Wake on request	No	Yes
HTTPS preview URLs	Yes	No
Raw TCP inbound	Yes	Not published
Public IPv4	No	No
Egress allowlist	No	Yes
Secret proxy	Yes	No
Secret proxy for any API	Yes	No
Preinstalled agents	Yes	Yes
Agent harness API	Yes	No
MCP server	No	Yes
GPU	No	Yes
Windows	No	No
Arm64	No	Not published
Self-hosting	No	No
BYOC	No	No
Open source	No	Yes
Scoped API keys	Yes	Not published
Spend limits	Yes	Yes
Usage per sandbox (API)	Yes	No
Audit logs	No	Yes
SSO	No	Yes
SOC 2	No	Yes
HIPAA	No	Yes
EU data residency	Yes	Yes
Zero data retention	Yes	Yes

Performance

boat26.69 runs/s

KernelNot measured

There is no comparable measurement. Kernel was not in StarSling's public CPU benchmark and does not publish how many vCPUs a browser gets, so there is no number to set against boat's 26.69 runs per second at 4 vCPU / 8 GB. Kernel does publish cold starts under 20 ms for its unikernels.

Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Kernel has no published run in this suite yet, so there is no like-for-like number to compare.

Pricing in five scenarios

Each bill is priced from the providers' public price lists by the open Battleships engine, with the cheapest plan that runs the scenario.

Scenario	boat, a month	Kernel, a month
One coding agent, workdays 4 vCPU / 8 GB, 50 GB disk, 8 hours a day, 22 days a month, files kept between days	$20 · $20/mo	$5 · Free / Developer · with limits
One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month	$26 · $20/mo	$34 · Free / Developer · with limits
50 agents in parallel 50 machines of 4 vCPU / 8 GB at once, 8-hour sessions, 1,100 sessions a month, Docker inside	$317 · $20/mo × 3 seats	$625 · Start-Up · with limits
Sandboxes for your users 2 vCPU / 4 GB, 30,000 sessions of 10 minutes a month, up to 300 at once	$200 · $100/mo × 2 seats	$420 · Start-Up · with limits
1,000 short jobs at once 2 vCPU / 4 GB, 1,000 at once, 3 minutes each, 200,000 jobs a month	$2,000 · $2000/mo · with limits	$747 · Start-Up · with limits

boat: You pick a monthly plan from $20, and all of it becomes usage credit spent per second on running sandboxes. A stopped sandbox costs nothing and keeps its disk.

Kernel: Kernel bills $0.0000166667 per GB-second of memory while a browser is active: a 1 GB headless browser and an 8 GB headful one cost different amounts for the same hour. Standby and proxies are free, and plans of $0, $30 and $200 a month include $5, $10 and $50 of usage.

Limits in those scenarios

The Kernel prices in the table are for a 1 GB headless browser, the closest thing it sells, so none of them is a 4 vCPU / 8 GB machine with a 50 GB disk, and none keeps files after the browser is deleted. Kernel also caps browsers at 150 at once on Start-Up, counting standby and pool browsers, so 300 sandboxes for your users and 1,000 short jobs at once need Enterprise. On boat, the 1,000-job burst is the one that does not fit: bursts above 90 starts a minute are queued, and it needs more starts per day than the top plan allows.

Scenario	boat	Kernel
One coding agent, workdays	None that bite	missing persistent disk machine size not published browser-session product, not a general sandbox different kind of product: browser session
One agent that never stops	None that bite	missing persistent disk machine size not published browser-session product, not a general sandbox different kind of product: browser session
50 agents in parallel	None that bite	missing persistent disk, Docker inside machine size not published browser-session product, not a general sandbox different kind of product: browser session
Sandboxes for your users	None that bite	Start-Up: max 150 concurrent machine size not published browser-session product, not a general sandbox different kind of product: browser session
1,000 short jobs at once	max 2,400 starts/day (needs ~6,667) max 600 starts/hour (needs ~1,000) bursts above 90 starts/min are queued (a burst of 333 takes ~4 min to start)	Start-Up: max 150 concurrent machine size not published browser-session product, not a general sandbox different kind of product: browser session

Which one should you use?

Use Kernel when

your agent only needs a browser: stealth scraping behind CAPTCHAs, saved logins, session replays, or browsers in the US or Asia that cost nothing while idle.

Stealth, proxies and CAPTCHAs. Useful for scraping sites that block bots: Kernel's stealth mode routes through ISP proxies and solves CAPTCHAs, and proxies cost nothing extra.
Free standby with memory kept. Useful if your agents sit idle between steps: a Kernel browser stops charging after 5 seconds idle and comes back with its pages loaded.
US and Asia regions, plus browser tooling. Useful if your users are in the US or Asia, or you want saved logins and session replays without building them.

Use boat when

your agent browses and also works: installs, builds, Docker and dev servers on a full VM with a disk that stays, a 60fps desktop and coding agents built in.

A whole machine, not only a browser. An agent that browses and then has to install packages, run a dev server or build in Docker needs a second machine next to a Kernel browser, and you wire the two together yourself.
Files that stay, and a fork of a running sandbox. Downloads, repos and notes an agent made inside a Kernel browser are gone when it is deleted, so long tasks must copy files out through the file API before the timeout.
Coding agents and a key proxy built in. With vault fill, a prompt-injected page or an extension can read a password once it is typed in. With boat's proxy the real key never enters the machine, so there is nothing to read.

Questions people ask

Is boat cheaper than Kernel?

The two price different things: the table sets a 4 vCPU / 8 GB boat VM against a 1 GB headless Kernel browser that keeps no disk. One agent running all month comes to $26 on boat and $34 on Kernel, 50 agents in parallel to $317 against $625, and sandboxes for your users to $200 against $420. Kernel's free plan covers the workday scenario but without a disk, and for 1,000 short jobs at once neither fits.

Can a Kernel browser run Docker or a coding agent?

Kernel's browser is a single-purpose unikernel for Chromium, and its docs document no container runtime. You can run commands in it and deploy agent code as a Kernel app, including a Claude Agent SDK template. On boat each sandbox is a full VM with Docker and coding agents already installed.

Does boat have stealth mode or CAPTCHA solving like Kernel?

No. boat runs Chromium on datacenter IPs and does not solve CAPTCHAs. If you scrape sites that block bots at volume, Kernel's ISP and residential proxies and CAPTCHA solver are built for that.

Can I use boat and Kernel together?

Yes. An agent on a boat sandbox can open a Kernel browser over its API and CDP, and keep its code, files and tools on the boat VM. That puts stealth browsing on Kernel and the rest of the work on a machine that keeps its disk.

Where does my data run?

boat runs only in the EU (Germany, Finland and France), with EU data residency and a zero data retention option. Kernel runs in us-east by default and offers eu-west and ap-southeast on the Start-Up and Enterprise plans.

Is boat SOC 2 compliant?

SOC 2 is in progress. We're open about where we stand: live status at status.ascii.dev and our data retention policy at docs.boat.dev/data-retention. Kernel lists SOC 2 and HIPAA compliance on its Enterprise plan.

Start a sandbox

Install the CLI, then run boat new.

7-day free trial