Vercel Sandbox vs Railway
Vercel Sandbox runs short bursts of untrusted code in Firecracker microVMs across 19 regions, and each session stops after 24 hours. Railway is an app platform that added sandbox VMs in 2026; they sit next to your apps and databases and are destroyed when they go idle.
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.
Railway
Railway is a cloud platform for deploying web apps, servers and databases, which now also sells sandboxes and cloud agents.
Railway's main product is app hosting: you deploy services and databases as containers on its own hardware. In 2026 it added Sandboxes, isolated Linux VMs you create from the CLI or a TypeScript SDK, run commands in and destroy, and Cloud Agents, a personal VM for running a coding agent, in early access. It suits teams already hosting on Railway who want throwaway machines next to their apps.
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 | Railway: 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 needs machines that keep their work; Vercel cuts sessions at 24 hours and Railway destroys idle sandboxes, so boat ranks 3rd with a full fit. | 244th of 367, with limits $3,351 a month | 51st of 367, with limits $342 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Railway fits an always-on assistant with the idle timeout set to 0 or a Cloud Agent, while Vercel stops each session after 24 hours. | 257th of 366, with limits $3,657 a month | 16th cheapest of 366 $3,977 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 fit short code bursts well and bill CPU only while it is used; Vercel Sandbox ranks 22nd and Railway ranks 36th on cost. | 22nd cheapest of 345 $216 a month | 36th cheapest of 345 $413 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 Vercel Sandbox ranks 15th and fits cleanly, while Railway allows 100 sandboxes per environment on Pro, so 300 at once means several environments; boat ranks first. | 15th cheapest of 361 $1,267 a month | 42nd of 361, with limits $290 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 for many short parallel rollouts thanks to its high concurrency; Railway's per-environment cap makes it a compromise. | 3rd cheapest of 360 $15,761 a month | 78th of 360, with limits $4,450 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 | 108th of 364, with limits $364 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 Both fit CI runners at similar ranks, and Vercel documents Docker inside while Railway's sandbox docs do not mention it. | 107th cheapest of 377 $1,144 a month | 113th cheapest of 377 $1,210 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Railway's Cloud Agents keep a disk and can sleep and wake, so Railway fits a dev box; on Vercel it restarts every 24 hours and loses its running processes. | 276th of 368, with limits $145 a month | 66th cheapest of 368 $89 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 has a desktop to stream or drive, so computer-use agents are a compromise on both; boat ranks 6th with a 60fps desktop built in. | 235th of 369, with limits $952 a month | 77th of 369, with limits $103 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 | 259th of 367, with limits $486 a month | 53rd of 367, with limits $93 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 | 60th cheapest of 346 $570 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 | 109th of 338, with limits $2,988 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 | 43rd of 360, with limits $574 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 | Railway | boat |
|---|---|---|---|
| Isolation | Firecracker microVM with its own kernel | Sandboxes are isolated Linux VMs; app services are containers | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Longest session | 24 hours on Pro and Enterprise, 45 minutes on Hobby; resume starts a new session | No set maximum; destroyed after the idle timeout (30 minutes by default, 0 for never) | No cap on paid plans (--no-auto-stop); default TTL 1 hour, changeable |
| Saving files | Filesystem snapshot on stop, kept 30 days after last use by default, billed per GB-month | Only the checkpoints you take; the sandbox is gone when destroyed | Snapshot every minute while running and on stop; a stopped sandbox costs nothing |
| Docker and nested virtualization | Docker with sudo; no nested virtualization | Root shell on Ubuntu; the sandbox docs do not mention Docker or /dev/kvm | Docker, root, systemd and /dev/kvm on every machine |
| Base images | Your own OCI images from a Dockerfile, via Vercel Container Registry | Templates built from ordered steps (apt packages, env, commands) and cached | Named snapshots (templates), shareable by code; no Dockerfile builds |
| Desktop, browser, computer use | None; headless Linux only | Headless: terminal, exec and SSH only | 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 Code, Codex, OpenCode and Pi preinstalled; you run them headless through exec | Claude Code, Codex, pi, OpenCode and more, with an API to prompt, steer and stream events |
| Keys kept outside the sandbox | Credentials brokering injects headers for any HTTPS domain you allow | Secrets go into the sandbox as environment variables, or are saved in a checkpoint | Credentials proxy for model providers and any HTTPS API you register; switch to another account when credits run out |
| Inbound access | Public URLs for up to 15 ports, no built-in auth; no raw TCP or public IP | Up to 10 public HTTPS domains, set only at creation; SSH and port forwarding | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP; dedicated IPv6 or IPv4 |
| Egress rules | Allow-all, deny-all or a domain and CIDR allowlist, changeable while running | No published egress allowlist for sandboxes | No provider-side allowlist; firewall inside the VM |
| Apps and databases next to the sandbox | Part of Vercel's web app platform; sandboxes can use your project's login tokens | Postgres, Redis and services in the same project; a sandbox can join their private network | No hosted databases or app services; host your own inside a sandbox |
| Biggest sandbox | 8 vCPU / 16 GB on Pro, 32 vCPU / 64 GB on Enterprise | 8 vCPU / 8 GB on Hobby, 32 vCPU / 32 GB on Pro | 8 vCPU / 16 GB on the $20 plan, 16 vCPU / 32 GB from $100 |
| Sandboxes at once | Up to 10,000 on Pro; vCPU allocation starts at 150 a minute and climbs with steady use | 50 per environment on Hobby, 100 on Pro; Enterprise can ask for more | 100 to 2,000 by plan |
| Regions | 19 regions across the US, Europe, Asia, South America, Africa and Australia | US West, US East, Amsterdam and Singapore | EU only: Germany, Finland, France |
Every feature Battleships tracks (43)
| Feature | Vercel Sandbox | Railway | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Not published | Yes |
| Nested virtualization | No | No | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Not published | Not published | Yes |
| Desktop GUI | No | No | Yes |
| Browser | No | Yes | Yes |
| Computer-use API | No | No | Yes |
| SSH | No | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | Yes | Yes |
| Automatic snapshots | Yes | No | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | Yes | Yes | Yes |
| Memory fork | No | No | 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 | No | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | No | No | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | No | No |
| Secret proxy | Yes | No | Yes |
| Secret proxy for any API | Yes | No | Yes |
| Preinstalled agents | Yes | Yes | Yes |
| Agent harness API | No | Yes | Yes |
| MCP server | Yes | Yes | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | No | No | No |
| Self-hosting | No | No | No |
| BYOC | No | Yes | No |
| Open source | No | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | Yes | Yes | Yes |
| Usage per sandbox (API) | No | No | Yes |
| Audit logs | Not published | Yes | No |
| SSO | Yes | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | Yes | Yes | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
On StarSling's Node.js build-and-test benchmark at 4 vCPU / 8 GB, boat did 26.69 runs per second and Vercel Sandbox did 12.96, so boat finished about twice as many runs in the same time. Railway has no result in that benchmark yet, so we cannot say how it compares. This measures CPU speed only, not start time.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Railway 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 | Vercel Sandbox, a month | Railway, 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 | $16 · Hobby · with limits | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $236 · Pro · with limits | $70 · Hobby · 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 | $2,884 · Pro | $739 · Hobby · 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 | $828 · Pro | $223 · Pro · 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 | $3,152 · Pro | $781 · Pro · with limits | $2,000 · $2000/mo · with limits |
Vercel Sandbox: Vercel charges for CPU only while your code uses it, but bills memory for the whole time the sandbox runs, idle 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.
Railway: Railway bills sandboxes per second at $50 per vCPU-month on CPU used and $50 per GB-month on memory in use, which keeps billing while a sandbox waits until it is destroyed. Railway does not publish a price for sandbox disk or checkpoints, so our Railway bills leave disk out.
Railway: boat charges a flat price per size, per second, only while the machine runs, and a stopped sandbox costs nothing. Plans start at $20 a month, and all of the fee is usage credit.
Limits in those scenarios
Railway is marked as not a clean fit in every scenario because it is an app platform first and does not publish a sandbox disk price, so its bills count CPU and memory only. Its cap of 100 sandboxes per environment on Pro means 300 sandboxes for your users or 1,000 jobs at once need several environments, and Docker inside is not confirmed for the 50-agent fleet. Vercel fits every scenario except one agent that never stops, where each session ends at 24 hours. boat fits every scenario except the 1,000-job burst, where even the $2,000 plan allows 600 starts an hour.
| Scenario | Vercel Sandbox | Railway | boat |
|---|---|---|---|
| One coding agent, workdays | None that bite |
| None that bite |
| One agent that never stops |
|
| 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 | None that bite |
|
|
Which one should you use?
Use Vercel Sandbox when
you run many short bursts of untrusted code at high concurrency, need regions outside the US and Europe, or want a firewall you can change from outside.
- Big bursts of short jobs. Useful for code interpreters and RL rollouts: Vercel fits 1,000 short jobs at once, where Railway caps 100 per environment on Pro.
- Regions all over the world. Useful if your users are spread out: Vercel Sandbox runs in 19 regions, from Virginia to Tokyo and Sydney.
- A firewall you control from outside. A running sandbox can be switched to deny-all, or to a list of allowed domains, without a restart.
Use Railway when
your app and databases already live on Railway and you want sandboxes on the same private network, or need machines up to 32 vCPU on a self-serve plan.
- Your apps and databases in one place. Useful if your app already runs on Railway: sandboxes can join the same private network as your Postgres and services.
- No 24-hour cut-off. Useful for long tasks: with the idle timeout set to 0, a Railway sandbox runs until you destroy it.
- Bigger machines on the self-serve plan. Useful for heavy builds: Railway Pro allows sandboxes up to 32 vCPU / 32 GB, where Vercel Pro stops at 8 vCPU.
Where boat fits
Both Vercel Sandbox and Railway are built for sandboxes that come and go: Vercel stops them at 24 hours and Railway destroys them when idle. If your agents work for hours or days on one machine, with Docker, a desktop and an API to drive them, look at boat. It is not the pick for 1,000 short jobs at once, where Vercel fits and boat hits its start limits.
Work survives a pause
Vercel ends each session at 24 hours and restarts every process; Railway destroys a sandbox after 30 idle minutes unless you set the timeout to 0, and then memory bills until you destroy it. boat saves the disk every minute and a stopped machine costs nothing.
A desktop, Docker and KVM
Neither has a screen, so an agent cannot open the app it built in a browser. Vercel has no nested virtualization, and Railway's sandbox docs do not mention Docker or /dev/kvm. boat has all of them, with root and systemd.
Agents driven from outside, on a faster CPU
On both you start each agent as a command and parse its output, and on Railway its key sits inside the VM. boat gives you a prompt, steer and events API, a credentials proxy, and did about twice Vercel's CPU runs per second.
Use boat when your agents work for hours or days on one machine: a full VM that keeps its disk, with Docker, /dev/kvm, a desktop and an API to drive the agents inside from outside. Compare it one to one: boat vs Vercel Sandbox and boat vs Railway.
Questions people ask
Is Vercel Sandbox cheaper than Railway?
Railway's bills come out lower in all five of our scenarios: $16 vs $57 for one workday agent, $739 vs $2,884 for 50 agents in parallel, and $781 vs $3,152 for 1,000 short jobs at once. But Railway's numbers leave out disk, which it does not price, and its 100-per-environment cap means several of those jobs do not fit cleanly. boat comes to $20, $317 and $2,000 for the same three, though the burst hits boat's start limits.
Which is faster, Vercel Sandbox or Railway?
We cannot say, because Railway has no result in StarSling's public benchmark yet. Vercel Sandbox did 12.96 Node.js build-and-test runs per second at 4 vCPU / 8 GB, and boat did 26.69 on the same test.
Can Vercel Sandbox or Railway run Docker?
Vercel's docs say you can run Docker inside a sandbox with sudo, but there is no nested virtualization. Railway sandboxes give you a root shell on Ubuntu, but the sandbox docs do not mention Docker or /dev/kvm. boat has Docker, systemd and /dev/kvm on every machine.
Can either run an agent 24/7?
Not as one Vercel session: it stops after 24 hours on Pro, and the resumed sandbox starts its processes over. Railway can, if you set the idle timeout to 0 or use a Cloud Agent, and memory bills the whole time. One agent that never stops comes to $236 on Vercel, $70 on Railway without disk, and $26 on boat.
Are both real virtual machines?
Yes. Vercel runs each sandbox in a Firecracker microVM with its own kernel, and Railway's docs call each sandbox an isolated virtual machine, while its regular app services are containers. boat runs every sandbox as a full VM too.
Where do they run?
Vercel Sandbox runs in 19 regions, with iad1 in the US as the default. Railway runs in California, Virginia, Amsterdam and Singapore, and new sandboxes start in US West unless you pick a region. boat runs only in the EU, in Germany, Finland and France.
Try boat
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