Vercel Sandbox vs Freestyle
Vercel Sandbox runs short jobs in Firecracker microVMs across 19 regions, and each session stops after 24 hours. Freestyle gives each agent a full KVM VM with systemd and nested virtualization that can run with no time cap, pause with its memory and wake on the next request.
The companies and products
Vercel Sandbox
Vercel is a cloud platform for web apps and agents, and Vercel Sandbox is its product for running untrusted or agent-written code in isolated Linux microVMs.
Each sandbox is a Firecracker microVM with its own kernel, started from a Vercel image, your own OCI image, or a saved snapshot. You drive it with the JavaScript or Python SDK or the sandbox CLI: run commands, move files, open ports, and set network rules. It is aimed at code interpreters, app builders, test runs and agent tools, and Vercel's docs say it is not meant to run nonstop.
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.
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. “22nd cheapest of 345” means 21 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 | Vercel Sandbox: price rank | Freestyle: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Neither has a desktop or browser for an agent to check the app it built, and Vercel also stops each session at 24 hours; boat ranks 3rd with both built in. | 244th of 367, with limits $3,351 a month | 241st of 367, with limits $3,311 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Freestyle VMs can run all month with no session cap, while Vercel's docs say sandboxes are not designed to run continuously; both are a compromise here, and boat ranks 5th. | 257th of 366, with limits $3,657 a month | 263rd of 366, with limits $4,195 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 Vercel Sandbox ranks 22nd and Freestyle ranks 40th: Vercel bills CPU only while code uses it, and Freestyle can pause a VM with its memory and wake it on the next request. | 22nd cheapest of 345 $216 a month | 40th cheapest of 345 $482 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 | 15th cheapest of 361 $1,267 a month | 16th cheapest of 361 $1,358 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 Vercel Sandbox ranks 3rd thanks to very high concurrency on Pro, while Freestyle Pro caps at 400 VMs at once, though it can fork a running VM with its memory. | 3rd cheapest of 360 $15,761 a month | 107th of 360, with limits $6,600 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 | 69th cheapest of 364 $1,508 a month | 53rd cheapest of 364 $1,046 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 Vercel fits CI runs fully, while Freestyle's own docs send sustained heavy CPU work elsewhere; boat ranks 4th and did about twice Vercel's CPU work per second. | 107th cheapest of 377 $1,144 a month | 168th of 377, with limits $625 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB A dev box that stays up all day fits Freestyle, while on Vercel it restarts every 24 hours and loses its running processes. | 276th of 368, with limits $145 a month | 98th cheapest of 368 $151 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 ships a desktop, so on both you build the screen, VNC and input layer yourself; boat ranks 6th with a 60fps desktop and computer use built in. | 235th of 369, with limits $952 a month | 234th of 369, with limits $940 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 Vercel has no browser feature and Freestyle has a guide to install Chromium and a display yourself; boat ranks 7th with Chromium ready in every sandbox. | 259th of 367, with limits $486 a month | 257th of 367, with limits $482 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 | 277th of 346, with limits $468 a month | 278th of 346, with limits $482 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 | 234th of 338, with limits $9,960 a month | 183rd of 338, with limits $6,560 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 | 283rd of 360, with limits $554 a month | 272nd of 360, with limits $482 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 | Vercel Sandbox | Freestyle | boat |
|---|---|---|---|
| Isolation | Firecracker microVM with its own kernel | Full KVM VM with its own kernel on bare metal servers | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| CPU benchmark (4 vCPU / 8 GB) | 12.96 runs/s | 9.64 runs/s | 26.69 runs/s |
| Longest session | 24 hours on Pro and Enterprise, 45 minutes on Hobby; resume starts a new session | No cap; runs until you pause, stop or delete it, or set your own limit | No cap on paid plans (--no-auto-stop); default TTL 1 hour, changeable |
| Pause and resume | Filesystem snapshot on stop; processes and memory start over | Pause saves memory and disk; the same processes resume where they left off | Disk saved every minute and on stop; resume boots the machine again |
| Fork and wake | New sandboxes boot from a saved filesystem snapshot; no wake on request | Clone a running VM with its memory; a paused VM wakes on the next request | Fork a running sandbox with its disk; a stopped sandbox is started by API |
| Docker and nested virtualization | Docker with sudo; no nested virtualization | Docker from boot, systemd as pid 1, full KVM support | Docker, root and systemd, with /dev/kvm for Android emulators and VMs |
| Desktop, browser, computer use | None; headless Linux only | Guides to install GNOME or Xvfb, VNC and Chromium yourself | 60fps desktop and Chromium, computer-use and browser-control APIs, embeddable stream |
| Coding agents | Claude Code, Codex, OpenCode and pi preinstalled; you start them as commands | claude, codex, opencode and openclaw preinstalled, driven through exec or a terminal | Seven agents preinstalled, with an API to prompt, steer and stream events |
| Custom images | Your own OCI images from a Dockerfile, via Vercel Container Registry | Your own snapshots built on the Ubuntu base; no OCI images | Named snapshots (templates), shareable by code; no Dockerfile builds |
| Biggest machine | 8 vCPU / 16 GB on Pro, 32 vCPU / 64 GB on Enterprise | 32 vCPU / 64 GiB on Pro, 64 / 128 with custom limits | Up to 16 vCPU / 32 GB on the $100 plan and above |
| Inbound access | Public URLs for up to 15 ports, no built-in auth; no raw TCP or public IP | HTTPS on free style.dev names or your own domain, forward auth, other public protocols | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP; dedicated IPv6 or IPv4 |
| Outbound rules | Allow-all, deny-all or a domain and CIDR allowlist, changeable while running | Default-deny firewall with allow rules by IP, VM, VPC or exact domain | Open internet, no provider-side allowlist; firewall inside the VM |
| Keys kept outside the sandbox | Credentials brokering injects headers for any HTTPS domain you allow | Credentials injected at the edge for HTTPS headers, Postgres and S3 | Credentials proxy for model providers and any HTTPS API; switch a credential to another account when one runs out |
| Regions | 19 regions across the US, Europe, Asia, South America, Africa and Australia | Not listed; the docs name a San Jose, US data center | EU only: Germany, Finland, France, with zero data retention |
Every feature Battleships tracks (43)
| Feature | Vercel Sandbox | Freestyle | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Yes | Yes |
| Nested virtualization | No | Yes | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Not published | Yes | Yes |
| Desktop GUI | No | No | Yes |
| Browser | No | No | Yes |
| Computer-use API | No | No | Yes |
| SSH | No | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | Yes | Yes |
| Automatic snapshots | Yes | Yes | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | Yes | Yes | Yes |
| Memory fork | No | Yes | No |
| Custom image (Docker or snapshot) | Yes | Yes | Yes |
| ≥24 h sessions | Yes | Yes | Yes |
| Idle auto-stop | No | Yes | No |
| Wake on request | No | Yes | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | No | Yes | 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 | Yes | No | No |
| GPU | No | Yes | 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 | Not published | Yes | Yes |
| Spend limits | Yes | Not published | Yes |
| Usage per sandbox (API) | No | No | Yes |
| Audit logs | Not published | Yes | No |
| SSO | Yes | Yes | No |
| SOC 2 | Yes | Not published | No |
| HIPAA | Yes | Not published | No |
| EU data residency | Yes | No | 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, Vercel Sandbox did 12.96 runs per second and Freestyle did 9.64, so Vercel finished about a third more work in the same time. boat did 26.69, about twice Vercel and 2.8 times Freestyle. This measures CPU speed only, not start time, where Freestyle advertises about 65 ms.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite.
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 | Vercel Sandbox, a month | Freestyle, 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 | $57 · Pro | $27 · Free | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $236 · Pro · with limits | $159 · Free | $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 | $2,884 · Pro | $2,139 · Pro | $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 | $828 · Pro | $581 · Pro | $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 | $3,152 · Pro | $1,305 · Pro · with limits | $2,000 · $2000/mo · with limits |
Vercel Sandbox: Vercel charges for CPU only while your code uses it, but charges for memory for the whole time the sandbox runs, idle time included, plus a small fee per sandbox created and a monthly fee per GB of snapshots. The $20 Pro credit is shared with your other Vercel usage.
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. Hobby and Pro set a $50 or $500 monthly minimum that counts as usage, and a paused VM bills only for storage.
Freestyle: boat charges a flat price per size, per second, only while the machine runs, and a stopped sandbox costs nothing and keeps its disk. Plans start at $20 a month, and all of the fee is usage credit.
Limits in those scenarios
For one agent that never stops, Vercel ends each session at 24 hours and running processes start over, while Freestyle runs on but has no idle timeout by default, so it bills until you pause it. For 1,000 short jobs at once, Vercel fits, but Freestyle Pro caps at 400 concurrent VMs. boat does not fit that burst either: even the $2,000 plan allows 600 starts an hour and queues bursts above 90 starts a minute.
| Scenario | Vercel Sandbox | Freestyle | boat |
|---|---|---|---|
| One coding agent, workdays | None that bite | 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 | None that bite |
| Sandboxes for your users | None that bite | None that bite | None that bite |
| 1,000 short jobs at once | None that bite |
|
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Which one should you use?
Use Vercel Sandbox when
you run many short bursts of untrusted code, need to run close to users around the world, or want to boot from your own Dockerfile.
- Regions all over the world. Useful if your users are spread out: Vercel Sandbox runs in 19 regions, from Virginia to Tokyo and Sydney.
- Huge bursts of short jobs. For many short runs at once, Pro allows far more parallel sandboxes than Freestyle Pro's 400, and CPU is billed only while used.
- Images from your Dockerfile. Useful if you already have a Dockerfile: build it into an OCI image and boot sandboxes straight into it.
Use Freestyle when
your VMs must keep running or sleep between requests and resume with their memory, or when you need nested virtualization or machines bigger than 16 vCPU.
- VMs that keep running. Useful for agents that live on one machine: a Freestyle VM has no session cap, while Vercel stops each session at 24 hours.
- Memory pause, live fork and wake on request. Useful for VMs that sleep between requests: they resume the same processes and can wake on the next incoming traffic.
- A full VM with nested virtualization. Useful for emulators or VMs inside: Freestyle runs systemd as pid 1 and supports KVM, which Firecracker does not offer.
Where boat fits
If your agents work for hours on one machine, building, testing and checking what they built in a browser, look at boat. It gives each one a full VM on CPUs about twice as fast as either, a desktop and browser built in, and an API to drive the agents inside from outside.
Faster builds and tests
boat did 26.69 runs per second on the CPU benchmark, against 12.96 for Vercel Sandbox and 9.64 for Freestyle. Every install, build and test an agent waits on takes about two to three times as long on them.
A desktop and a browser, ready
Neither ships a screen, so an agent cannot open the app it built to see if it works. On Vercel you build the desktop yourself; on Freestyle you install GNOME or Xvfb, VNC and Chromium and wire up clicks yourself.
Agents you drive from outside
Both preinstall coding agent CLIs, but you start them as commands and parse their output yourself. boat adds an API to prompt, steer and stream the agents inside, and can switch a credential to another account when one runs out.
Use boat when your agents do real work for hours: builds, tests, Docker, emulators and a desktop with a browser, on fast CPUs, with an API to drive the agents inside from outside. Compare it one to one: boat vs Vercel Sandbox and boat vs Freestyle.
Questions people ask
Is Vercel Sandbox cheaper than Freestyle?
In our scenarios Freestyle costs less in four of five: one workday agent is $27 a month on Freestyle against $57 on Vercel, and 50 parallel agents are $2,139 against $2,884. For 1,000 short jobs at once, Vercel fits at $3,152 while Freestyle Pro hits its 400 VM cap. boat is $20 a month for the workday agent and $317 for the 50 agents.
Which is faster, Vercel Sandbox or Freestyle?
On the hpc-sandbox-benchmarks CPU test at 4 vCPU / 8 GB, Vercel Sandbox did 12.96 runs per second and Freestyle did 9.64. boat did 26.69 on the same test. Freestyle advertises VM starts in about 65 ms, which this test does not measure.
Can Vercel Sandbox or Freestyle run 24/7?
Freestyle can: a VM has no session cap and runs until you pause, stop or delete it. Vercel Sandbox sessions stop after 24 hours on Pro and Enterprise; the sandbox can resume from its snapshot, but processes and memory start fresh.
Can both run Docker and Android emulators?
Both run Docker. Only Freestyle offers nested virtualization, so Android emulators and VMs inside the sandbox work there but not on Vercel's Firecracker microVMs. boat runs Docker and exposes /dev/kvm too.
Do Vercel Sandbox or Freestyle have a desktop for computer use?
No. Vercel Sandbox is headless only, and Freestyle has guides for installing a desktop, VNC and Chromium yourself. boat includes a 60fps desktop, Chromium, and computer-use and browser-control APIs.
Where do they run?
Vercel Sandbox runs in 19 regions around the world, with iad1 in the US as the default. Freestyle does not list regions; its docs name a San Jose, US data center. boat runs only in the EU (Germany, Finland and France).
Try boat
Install the CLI, then run boat new.
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