Freestyle vs Deno Sandbox
Freestyle gives each agent a full Linux VM with Docker and systemd that can run for as long as you like, pause with its memory and fork while running. Deno Sandbox gives short, locked-down runs a 2 vCPU Firecracker microVM that starts in under 200 ms and lives up to 30 minutes.
The companies and products
Freestyle
Freestyle sells full Linux virtual machines for AI agents, built for long running, complex tasks.
Each Freestyle VM is a KVM virtual machine with its own kernel, booted from an Ubuntu base snapshot with systemd, Docker and coding agent CLIs preinstalled. VMs can be paused with their memory, snapshotted while running, forked and woken by the next request, and every VM starts behind a default-deny firewall. It is built for teams that give each agent or each user its own machine, driven from a TypeScript SDK, a CLI or an API.
Deno Sandbox
Deno Sandbox is part of Deno Deploy, the hosting platform from the company behind the Deno runtime, and runs untrusted or AI-generated code in Linux microVMs.
Each sandbox is a Firecracker microVM with 2 vCPU, up to 4 GB of memory and a 10 GB disk that is wiped when it ends, created from a TypeScript or Python SDK. Outbound traffic goes through a proxy that can enforce a host allowlist and swap placeholder secrets for real ones. It is built for short runs of agent or user code, and a sandbox can be promoted to a Deno Deploy app.
- Isolation
- Firecracker microVM per sandbox
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. “40th cheapest of 345” means 39 of the other 344 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 | Freestyle: price rank | Deno Sandbox: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month A software factory runs Docker, installs and builds for hours, which fits Freestyle's full VMs but outlasts Deno's 30-minute lifetime and 2 vCPU shape; boat adds CPUs that did 2.8 times Freestyle's work on the benchmark. | 241st of 367, with limits $3,311 a month | 290th of 367, with limits $5,665 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An assistant that lives on its machine all month runs on Freestyle or boat, while a Deno sandbox ends after 30 minutes and wipes its root disk. | 263rd of 366, with limits $4,195 a month | 287th of 366, with limits $5,803 a month | 5th cheapest of 366 $657 a month |
| Code interpreter bursts 100 at once · 1 vCPU / 2 GB · 200,000 sessions of 1 min a month Both suit short code runs: Deno starts in under 200 ms and bills CPU only while code runs, and Freestyle pauses VMs with their memory and wakes them on the next request. | 40th cheapest of 345 $482 a month | 141st of 345, with limits $329 a month | 186th of 345, with limits $2,000 a month |
| Sandboxes for your users 300 at once · 2 vCPU / 4 GB · 30,000 sessions of 23 min a month Freestyle fits a sandbox per user with up to 400 at once on Pro, while Deno Builder allows 20 at once per region; boat also fits, with hosting token-protected by default. | 16th cheapest of 361 $1,358 a month | 148th of 361, with limits $1,863 a month | Cheapest of 361 $209 a month |
| RL rollouts 1,000 at once · 2 vCPU / 4 GB · 1,000,000 sessions of 3 min a month | 107th of 360, with limits $6,600 a month | 122nd of 360, with limits $7,963 a month | 34th of 360, with limits $2,000 a month |
| Agent evals 250 at once · 4 vCPU / 8 GB · 15,000 sessions of 20 min a month Eval runs that last longer than 30 minutes or need Docker fit Freestyle and boat, not Deno Sandbox as documented. | 53rd cheapest of 364 $1,046 a month | 296th of 364, with limits $1,563 a month | 10th cheapest of 364 $200 a month |
| CI runners 40 at once · 8 vCPU / 16 GB · 6,000 sessions of 12 min a month CI jobs that run Docker or Android emulators need Docker and nested virtualization, which Freestyle and boat document and Deno does not. | 168th of 377, with limits $625 a month | 304th of 377, with limits $731 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB | 98th cheapest of 368 $151 a month | 179th of 368, with limits $200 a month | 18th cheapest of 368 $26 a month |
| Computer-use agents 50 at once · 4 vCPU / 8 GB · 20,000 sessions of 15 min a month Neither Freestyle nor Deno ships a desktop: Freestyle has guides to install one yourself and Deno has none, while boat streams a Linux desktop at 60fps with computer use built in. | 234th of 369, with limits $940 a month | 280th of 369, with limits $1,583 a month | 6th cheapest of 369 $200 a month |
| Browser-use agents 50 at once · 2 vCPU / 4 GB · 30,000 sessions of 10 min a month On Freestyle you install Chromium and a display from its guides, and on Deno you would fit a headless browser into 4 GB yourself; boat has Chromium ready in every sandbox. | 257th of 367, with limits $482 a month | 284th of 367, with limits $783 a month | 7th cheapest of 367 $200 a month |
| Scraping & bots (startup scale) 50 at once · 1 vCPU / 2 GB · 100,000 sessions of 3 min a month | 278th of 346, with limits $482 a month | 286th of 346, with limits $573 a month | 6th cheapest of 346 $90 a month |
| Mass scraping & bots (undetectable) 1,000 at once · 1 vCPU / 2 GB · 3,000,000 sessions of 2 min a month | 183rd of 338, with limits $6,560 a month | 247th of 338, with limits $11,923 a month | 71st of 338, with limits $1,800 a month |
| Parallel red teaming 200 at once · 2 vCPU / 4 GB · 5,000 sessions of 30 min a month | 272nd of 360, with limits $482 a month | 251st of 360, with limits $367 a month | 2nd cheapest of 360 $200 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 | 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 | Can't run it |
Key features
| Feature | Freestyle | Deno Sandbox | boat |
|---|---|---|---|
| Isolation | Full KVM VM with its own kernel on bare metal servers | Firecracker microVM with its own kernel | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Machine size | 4 vCPU / 8 GiB on Free, up to 32 vCPU / 64 GiB on Pro, 64 / 128 with custom limits | 2 vCPU fixed, 768 MB to 4 GB memory, 10 GB disk | 4 vCPU / 8 GB by default, up to 16 vCPU / 32 GB on the $100 plan and above |
| CPU benchmark (4 vCPU / 8 GB) | 9.64 runs/s | Not measured; the fixed 2 vCPU shape cannot run the 4 vCPU test | 26.69 runs/s |
| Session length | No provider cap; a VM runs until you pause, stop or delete it | Up to 30 minutes; longer work can be promoted to a Deno Deploy app | No cap on paid plans; you set the time to live |
| Disk that persists | Disk is kept while running, paused or stopped, billed on allocated size | Root disk wiped when the sandbox ends; opt-in volumes of 300 MB to 20 GB, Chicago only | The whole disk is kept, saved every minute and on stop; a stopped sandbox costs nothing |
| Pause, snapshot and fork | Pause with memory, snapshot memory and disk, clone a running VM without pausing it | Read-only snapshots of a volume that new sandboxes can boot from; no fork | Automatic disk snapshots; fork a running sandbox with its disk |
| Root, Docker and nested virtualization | Yes; systemd is pid 1, Docker runs from boot, full KVM support | Root access; Docker and nested virtualization not documented | Docker, systemd and /dev/kvm for Android emulators and VMs |
| Start time | About 65 ms advertised; a paused VM wakes on the next request | Under 200 ms | Boots a full VM; a stopped sandbox is started by API |
| Desktop and browser | Guides to install GNOME or Xvfb, VNC and Chromium yourself | No desktop; a VS Code editor in the browser and SSH | Linux desktop streamed at 60fps, Chromium and computer use built in |
| Coding agents | claude, codex, opencode and openclaw preinstalled, driven through exec or a terminal | A root image with Claude Code, run through the shell command API | Seven agents preinstalled, with a prompt, steer and events API |
| Outbound rules | Default-deny firewall with allow rules by IP, VM, VPC or exact domain | Host allowlist per sandbox, enforced by a proxy outside the VM | Open internet, no provider-side allowlist |
| Keeping API keys out of the sandbox | Credentials injected at the edge for HTTPS headers, Postgres and S3; the VM must trust the Freestyle CA | Secrets swapped in on outbound requests to approved hosts; the sandbox only sees a placeholder | Credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out |
| Inbound access | HTTPS on free style.dev names or your own domain, forward auth, other public protocols | HTTPS URL per exposed port, public without authentication; SSH | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP |
| Regions | Not listed; the docs name a San Jose, US data center | Amsterdam and Chicago | EU only (Germany, Finland, France), zero data retention |
Every feature Battleships tracks (43)
| Feature | Freestyle | Deno Sandbox | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Not published | Yes |
| Nested virtualization | Yes | No | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Yes | Not published | Yes |
| Desktop GUI | No | No | Yes |
| Browser | No | No | Yes |
| Computer-use API | No | No | Yes |
| SSH | Yes | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | No | Yes |
| Automatic snapshots | Yes | No | Yes |
| Fork/clone | Yes | No | Yes |
| Live fork (no pause) | Yes | No | Yes |
| Memory fork | Yes | No | No |
| Custom image (Docker or snapshot) | Yes | Yes | Yes |
| ≥24 h sessions | Yes | No | Yes |
| Idle auto-stop | Yes | No | No |
| Wake on request | Yes | No | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | Yes | No | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | Yes | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | Yes | Yes | Yes |
| Preinstalled agents | Yes | Yes | Yes |
| Agent harness API | No | No | Yes |
| MCP server | No | No | No |
| GPU | Yes | No | No |
| Windows | No | No | No |
| Arm64 | No | No | No |
| Self-hosting | No | No | No |
| BYOC | No | No | No |
| Open source | No | No | No |
| Scoped API keys | Yes | Not published | Yes |
| Spend limits | Not published | Yes | Yes |
| Usage per sandbox (API) | No | No | Yes |
| Audit logs | Yes | Not published | No |
| SSO | Yes | No | No |
| SOC 2 | Not published | Yes | No |
| HIPAA | Not published | Yes | No |
| EU data residency | No | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
On the hpc-sandbox-benchmarks Node.js build-and-test loop at 4 vCPU / 8 GB, Freestyle did 9.64 runs per second and boat did 26.69, so boat did about 2.8 times the CPU work in the same time. Deno Sandbox has no comparable measurement: it is not in that benchmark, and its fixed 2 vCPU shape could not run the 4 vCPU test. This measures CPU speed only, not start time, where Freestyle advertises about 65 ms and Deno under 200 ms.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Deno Sandbox 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 | Freestyle, a month | Deno Sandbox, a month | boat, 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 | $27 · Free | $53 · Pro · with limits | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $159 · Free | $200 · Builder · with limits | $26 · $20/mo |
| 50 agents in parallel 50 machines of 4 vCPU / 8 GB at once, 8-hour sessions, 1,100 sessions a month, Docker inside | $2,139 · Pro | $2,779 · Builder · with limits | $317 · $20/mo × 3 seats |
| Sandboxes for your users 2 vCPU / 4 GB, 30,000 sessions of 10 minutes a month, up to 300 at once | $581 · Pro | $783 · Builder · with limits | $200 · $100/mo × 2 seats |
| 1,000 short jobs at once 2 vCPU / 4 GB, 1,000 at once, 3 minutes each, 200,000 jobs a month | $1,305 · Pro · with limits | $1,563 · Builder · with limits | $2,000 · $2000/mo · with limits |
Freestyle: Freestyle bills per second for the vCPU, RAM and disk allocated to a VM, busy or idle, after monthly allowances of 200 vCPU-hours, 400 GiB-hours of RAM and 60,000 GiB-hours of storage. On Free those allowances are hard stops; Hobby and Pro set a $50 or $500 monthly minimum that counts as usage.
Deno Sandbox: Sandboxes need the Pro plan at $20 a month or Builder at $200 a month; the fee is not credit but includes CPU, memory and egress allowances shared with your Deno Deploy apps. Past those, CPU costs $0.10 per hour of active CPU time and memory $0.025 per GiB-hour for the whole life of the sandbox.
Deno Sandbox: Plans start at $20 a month, and the whole fee is usage credit. You pay per second while a sandbox runs, and a stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Deno Sandbox fits none of the five scenarios as written: a sandbox lives up to 30 minutes and is fixed at 2 vCPU with up to 4 GB, and Builder allows 20 at once per region. Freestyle fits four of the five, though on Free the monthly allowances are hard stops and Pro allows 400 VMs at once, which is why it does not fit 1,000 short jobs at once. boat fits the same four; for that burst its top plan queues starts above 90 a minute, so none of the three fits it without a custom plan.
| Scenario | Freestyle | Deno Sandbox | boat |
|---|---|---|---|
| One coding agent, workdays | None that bite |
| None that bite |
| One agent that never stops | None that bite |
| None that bite |
| 50 agents in parallel | None that bite |
| None that bite |
| Sandboxes for your users | None that bite |
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Freestyle when
your agents need a full VM for hours, with Docker, more than 16 vCPU, a default-deny firewall, or a VM that pauses with its memory and wakes on the next request.
- Machines that stay and pause with their memory. For agents that work for hours or sleep between requests: no session cap, and a paused VM resumes the same processes.
- Bigger, fuller VMs. For heavy builds: Docker and nested virtualization run inside, and Pro VMs reach 32 vCPU / 64 GiB against Deno's fixed 2 vCPU.
- Live fork and more at once. For branching work or many users: clone a running VM without pausing it, with up to 400 VMs at once on Pro.
Use Deno Sandbox when
you run short pieces of untrusted code that must start in milliseconds, reach only the hosts you allow, and finish within 30 minutes, especially if you already deploy on Deno Deploy.
- Fast starts and active-CPU billing. For short bursts of code: a sandbox starts in under 200 ms and CPU bills only while code runs.
- Secrets and hosts locked at a proxy. For untrusted code: a proxy outside the VM blocks hosts not on your list and swaps in real secrets only for approved ones.
- A region in Europe and a path to Deno Deploy. For teams already on Deno Deploy: sandboxes run in Amsterdam or Chicago and can be promoted to Deploy apps.
Where boat fits
If your agents do real work for hours, with builds, tests, Docker, a desktop and a browser, look at boat. It gives each agent a full VM like Freestyle, without the 30-minute cap Deno has, on CPUs that did 2.8 times Freestyle's work on the same benchmark, plus a desktop and an API to drive the agents inside from outside.
Faster CPUs for builds and tests
Freestyle did 9.64 runs per second on the CPU benchmark and boat did 26.69, so every install and test waits almost three times as long there. Deno's fixed 2 vCPU could not run the test at all.
A desktop and browser, ready
Neither ships a desktop. On Freestyle you build GNOME or Xvfb, VNC and Chromium into your own snapshot, and Deno has no desktop. boat streams a Linux desktop at 60fps with Chromium and computer use built in.
Agents you drive from outside
Both preinstall coding agent CLIs that you start through exec or shell commands and parse yourself. boat adds an API to prompt, steer and follow them, and its credentials proxy can switch to another account when credits run out.
Use boat when your agents do real work for hours: builds, tests, Docker, emulators, a desktop and a browser, on fast CPUs, with an API to drive the agents inside from outside. Compare it one to one: boat vs Freestyle and boat vs Deno Sandbox.
Questions people ask
Is Freestyle cheaper than Deno Sandbox?
In all five scenarios on this page, Freestyle comes out lower: $159 against $200 for one agent running all month, and $581 against $783 for sandboxes for your users. Deno Sandbox does not fit any of them as written, and boat is lower than both in four of the five.
Which is faster, Freestyle or Deno Sandbox?
Deno Sandbox starts in under 200 ms and Freestyle advertises about 65 ms. For CPU work there is no comparison, since Deno is not in the benchmark; Freestyle did 9.64 runs per second there and boat did 26.69.
Can Freestyle or Deno Sandbox run Docker?
Freestyle runs Docker from boot, with systemd and full KVM support for nested virtualization. Deno's docs give root access but do not say Docker or nested virtualization works. boat runs Docker and systemd and exposes /dev/kvm.
How long can each sandbox run?
A Deno sandbox lives up to 30 minutes, and its root disk is wiped when it ends. Freestyle has no provider cap, so a VM runs and bills until you pause, stop or delete it. A boat sandbox has no cap on paid plans, and a stopped one costs nothing.
Can both keep API keys out of the sandbox?
Yes. Freestyle injects credentials at the edge for HTTPS, Postgres and S3, and Deno swaps placeholder secrets for real ones on requests to approved hosts. boat's credentials proxy covers model providers and any HTTPS API, and can switch to another account when credits run out.
Can I run a browser agent on either?
On Freestyle you install Chromium, a virtual display and VNC yourself from its guides. Deno Sandbox has no desktop. boat ships a 60fps desktop, Chromium and computer use in every sandbox.
Try boat
Install the CLI, then run boat new.
7-day free trial