Docker Cloud Sandboxes vs Instabox
Both give each coding agent its own microVM with Docker inside. Docker's is the sbx sandbox from your laptop running in the cloud for up to 24 hours, 10 at a time, while Instabox is a beta that launched on 2026-10-14 with one 4 vCPU / 8 GiB size, 5 machines per account and a desktop.
The companies and products
Docker Cloud Sandboxes
Docker Cloud Sandboxes runs Docker's sbx coding-agent microVMs on Docker-managed compute instead of your laptop.
Each sandbox is a microVM with its own Linux kernel and its own Docker Engine, started from the same sbx CLI you use locally, with Claude Code, Codex and other agents ready to run. You can move a sandbox from your laptop to the cloud and back, publish HTTPS ports and SSH in. It launched on September 24, 2026, is billed pay-as-you-go on a personal Docker account, and is built for developers who want their local agent sandboxes to keep going off their machine.
- Launched
- September 24, 2026
- Session length
- 1 hour by default, extendable to 24 hours from creation
- Default quota
- 10 concurrent and 50 stored sandboxes per account
- Regions
- Not published
Instabox
Instabox, made by InsForge, gives each AI agent its own Linux computer in the cloud. It launched on 2026-10-14 as an invite-only beta.
Each Instabox machine is a Firecracker microVM with its own kernel, root and Docker, started from one of four templates (agent-browser, universal, herdr or orca) or from your own snapshot. Every machine is 4 vCPU / 8 GiB with 20 GB of storage, and you drive it from a CLI, a TypeScript SDK or an HTTP API, with SSH, mosh, public port URLs and a desktop for computer use. It is aimed at developers who want a cloud box for a coding agent.
- Isolation
- Firecracker microVM per machine
- Machines per account
- 5, in any state: paused and stopped ones count
- Company
- InsForge AI, Inc.
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. “280th cheapest of 367” means 279 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 | Docker Cloud Sandboxes: price rank | Instabox: 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 many agents for days: Docker stops each sandbox 24 hours after creation and runs 10 at once, and Instabox allows 5 machines in any state. | 280th of 367, with limits $4,928 a month | No published price | 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 cannot do it in one Docker session; Instabox documents no maximum run time but pauses after 30 idle minutes unless you turn that off. | 276th of 366, with limits $5,110 a month | No published price | 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 | 119th of 345, with limits $233 a month | No published price | 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 Serving your own users needs many sandboxes at once: Docker allows 10 by default and Instabox 5 per account, while boat runs 100 on its $20 plan. | 136th of 361, with limits $1,628 a month | No published price | 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 | 114th of 360, with limits $7,000 a month | No published price | 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 Evals run side by side, so Docker's 10 at once and Instabox's 5 machines cap how many run together. | 167th of 364, with limits $1,400 a month | No published price | 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 that builds Android apps or VM images needs /dev/kvm, which boat exposes and neither Docker nor Instabox documents. | 172nd of 377, with limits $672 a month | No published price | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB A dev box that stays on all month does not fit Docker's 24-hour sessions; Instabox has SSH with mosh and no documented cap, and boat adds published plans. | 127th of 368, with limits $204 a month | No published price | 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 Computer-use agents need a screen: Docker's sandboxes are terminal only, Instabox has a desktop on one template, and boat streams a 60fps desktop. | 268th of 369, with limits $1,400 a month | No published price | 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 Browser agents need a browser inside the machine; Instabox's agent-browser template and boat ship one, Docker's cloud sandboxes do not. | 277th of 367, with limits $700 a month | No published price | 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 | 262nd of 346, with limits $350 a month | No published price | 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 | 190th of 338, with limits $7,000 a month | No published price | 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 | 248th of 360, with limits $350 a month | No published price | 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 | No published price | 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 | No published price | Can't run it |
Key features
| Feature | Docker Cloud Sandboxes | Instabox | boat |
|---|---|---|---|
| Isolation | MicroVM with its own Linux kernel and its own Docker Engine | Firecracker microVM with its own kernel and root | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Machine sizes | 1 vCPU / 2 GiB up to 16 vCPU / 32 GiB; amd64 or arm64 by account | One size for everyone: 4 vCPU / 8 GiB with 20 GB storage; other sizes are refused | Several sizes, up to 8 vCPU / 16 GB on the $20 plan and 16 vCPU / 32 GB on $100 and above |
| Session length | 1 hour by default, at most 24 hours from creation; resuming starts a new timer | No maximum documented; optional timeout of 1 minute to 24 hours, and a pause after 30 idle minutes unless turned off | No cap on paid plans; you set the time to live |
| Sandboxes at once | 10 concurrent and 50 stored by default; no published way to raise it | 5 machines per account, paused and stopped ones included | 100 on the $20 plan, up to 2,000 on higher plans, self-serve |
| Stop or pause | Stop keeps memory and files; resume picks up where it left off | Pause keeps memory and running programs; resume usually takes about a second | Disk saved every minute and on stop; start boots the machine again |
| Fork | Snapshot a running sandbox with disk or disk and memory, then restore it as a new sandbox | Fork copies a stopped machine only; saving a snapshot stops a running machine first unless the server allows a live save | Fork a running sandbox with its disk |
| Docker inside | Yes, its own Docker Engine; the agent runs as a non-root user with sudo | Docker and Docker Compose run inside, with root | Docker and Compose run inside, with root and systemd |
| Nested virtualization | Not documented | Not documented | Yes, /dev/kvm for Android emulators and VMs |
| Desktop and computer use | Terminal sessions only | Linux desktop with a browser on one template, screenshot and click API, shareable view or control links; you bring the model | 60fps Linux desktop with Chromium and a computer-use agent |
| Public port URLs | Public HTTPS URL per published port, not protected by Docker sign-in; not a TCP tunnel | HTTPS on up to 16 ports, open to anyone with the URL; offline while the machine is paused | HTTPS on up to 50 ports, token-protected by default; raw TCP too |
| SSH | SSH with Docker-issued certificates | SSH through a gateway with short-lived certificates, paste-anywhere SSH tokens and mosh | SSH into every sandbox |
| Outbound rules | Allow and deny rules by host, with allow-all, balanced and deny-all presets | Not documented | Open internet, no provider-side allowlist |
| Coding agents | Claude Code, Codex, Copilot, OpenCode and more, run and attached to from the sbx CLI | Templates and saved agent sign-ins in snapshots; you run the agent yourself | Seven agents preinstalled, with a prompt, steer and events API to drive them from outside |
| Regions | Not published | Not published | EU only (Germany, Finland, France) |
Every feature Battleships tracks (43)
| Feature | Docker Cloud Sandboxes | Instabox | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Yes | Yes |
| Nested virtualization | No | Not published | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Not published | Not published | Yes |
| Desktop GUI | No | Yes | Yes |
| Browser | No | Yes | Yes |
| Computer-use API | No | Yes | Yes |
| SSH | Yes | 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 | No | Yes |
| Memory fork | Yes | 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 | Not published | No | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | Not published | Not published | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | Not published | No |
| Secret proxy | Yes | No | Yes |
| Secret proxy for any API | Yes | No | Yes |
| Preinstalled agents | Yes | Not published | Yes |
| Agent harness API | No | Not published | Yes |
| MCP server | Yes | Not published | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | Yes | Not published | No |
| Self-hosting | No | Not published | No |
| BYOC | No | Not published | No |
| Open source | No | No | No |
| Scoped API keys | Not published | Yes | Yes |
| Spend limits | Not published | Not published | Yes |
| Usage per sandbox (API) | No | Yes | Yes |
| Audit logs | Not published | Not published | No |
| SSO | Yes | No | No |
| SOC 2 | No | Not published | No |
| HIPAA | No | Not published | No |
| EU data residency | No | Not published | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
Neither Docker Cloud Sandboxes nor Instabox has a comparable measurement: both are new and not in the hpc-sandbox-benchmarks runs, so this page makes no speed claim between them. boat did 26.69 runs per second on the same Node.js build-and-test benchmark at 4 vCPU / 8 GB, on dedicated AMD Ryzen 9 9950X hosts. Instabox says a new machine's shell is ready in under a second; that has not been measured here.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Docker Cloud Sandboxes and Instabox have 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 | Docker Cloud Sandboxes, a month | Instabox, 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 | $49 · Docker Agentic Platform (pay-as-you-go) | No published price | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $204 · Docker Agentic Platform (pay-as-you-go) · with limits | No published price | $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 | $2,464 · Docker Agentic Platform (pay-as-you-go) · with limits | No published price | $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 | $700 · Docker Agentic Platform (pay-as-you-go) · with limits | No published price | $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 | $1,400 · Docker Agentic Platform (pay-as-you-go) · with limits | No published price | $2,000 · $2000/mo · with limits |
Docker Cloud Sandboxes: Docker bills per second for the size you pick, from $0.07 an hour for 1 vCPU / 2 GiB to $1.12 an hour for 16 vCPU / 32 GiB, with no monthly fee. A stopped sandbox costs nothing, and volumes and egress are free.
Instabox: Instabox is free during the beta, with 5 machines per user, and has no published price yet, so no bill can be compared with Docker's or boat's.
Instabox: 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
Docker ends every sandbox 24 hours after creation, so one agent that never stops does not fit one session, and its default of 10 at once rules it out for 50 agents in parallel, sandboxes for your users and 1,000 short jobs at once. Instabox publishes no rate, so no scenario can be priced, and its 5 machines per account, paused and stopped ones included, are too few for the 50-agent and user-sandbox scenarios today. Every Instabox machine is 4 vCPU / 8 GiB, and an API exec call runs at most 10 minutes, 4 at once. boat has no session cap, but its start limits are lower than a 1,000-job burst needs, so even the $2,000 plan queues those starts.
| Scenario | Docker Cloud Sandboxes | Instabox | 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 |
| Sandboxes for your users |
|
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Docker Cloud Sandboxes when
you already run agents in sbx on your laptop and want a few of them to keep going in the cloud for up to a day, with memory kept across stops, a choice of sizes and outbound rules.
- The same sandbox on your laptop. If you already run sbx locally, the cloud is the same microVM and CLI, and you can move a sandbox either way.
- Fork a running sandbox with its memory. Agents that branch mid-task can snapshot a running sandbox with its memory and restore it as a new one.
- Sizes and outbound rules. Teams can pick from 1 to 16 vCPU, on amd64 or arm64, and limit where an agent connects by host.
Use Instabox when
you want to try up to 5 free 4 vCPU / 8 GiB agent machines during its beta, with a desktop template, memory pause and SSH with mosh.
- Free to try during the beta. During the invite-only beta, each account can run 5 machines of 4 vCPU / 8 GiB for free.
- A desktop for computer use. One template has a Linux desktop with a browser, a screenshot and click API, and shareable view or control links.
- No 24-hour limit, with memory pause. Its docs set no maximum run time, and a paused machine keeps its memory and running programs.
Where boat fits
Docker Cloud Sandboxes and Instabox both suit a handful of agents: Docker for up to a day each, Instabox for 5 machines of one size during its beta. When your agents run for days, by the dozen, need a screen or Android emulators, or serve work you do not want public, look at boat.
Runs as long and as wide as the work
Docker ends a sandbox 24 hours after creation and runs 10 at once, so your code must stop and resume long jobs. Instabox counts paused and stopped machines in its 5. boat has no session cap on paid plans and runs 100 at once from $20.
A whole machine, screen included
Neither documents /dev/kvm, so Android emulators and VM builds are out. Docker is terminal only, so you add a browser service, and Instabox's desktop is one template where you bring the model. boat has both, with a 60fps desktop.
Private URLs and agents you drive from outside
Port URLs on Docker and Instabox are open to anyone who has them, so you put your own login in front of each service. boat's carry a token by default, and its API prompts, steers and follows agents inside from outside.
Use boat when your agents run for days or by the dozen, need Android emulators, a desktop or private port URLs, or have to be driven from your own app through an API, on terms published today. Compare it one to one: boat vs Docker Cloud Sandboxes and boat vs Instabox.
Questions people ask
Is Docker Cloud Sandboxes cheaper than Instabox?
It can't be compared yet. Instabox is free during its beta and publishes no price, while Docker bills $0.28 an hour for 4 vCPU / 8 GiB, which comes to $49 a month for one coding agent on workdays. boat runs that same agent for $20 a month.
Which is faster, Docker Cloud Sandboxes or Instabox?
Neither has been benchmarked, so there is no fair answer yet. Instabox says a new machine's shell is ready in under a second, and its docs say a paused machine usually resumes in about a second. boat scored 26.69 runs per second at 4 vCPU / 8 GB.
Can Docker Cloud Sandboxes and Instabox run Docker?
Yes, both run Docker inside the sandbox, and Instabox also documents Docker Compose. Neither documents nested virtualization, so Android emulators and VMs are not covered. boat runs Docker with root and systemd and exposes /dev/kvm.
Can either run an agent for longer than 24 hours?
Not on Docker: a cloud sandbox ends at most 24 hours after creation. Instabox documents no maximum run time, but a machine pauses after 30 idle minutes unless you turn that off. boat has no session cap on paid plans.
How many sandboxes can I run at once?
Docker allows 10 concurrent and 50 stored per account by default. Instabox allows 5 machines per account, and paused and stopped ones count. boat's $20 plan runs 100 at once, and higher plans go up to 2,000.
Can I fork a running sandbox?
On Docker, yes: you can snapshot a running sandbox with its memory and restore it as a new one. Instabox's fork copies a stopped machine only. boat forks a running sandbox with its disk and keeps the original working.
Try boat
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