Unikraft Cloud vs Instabox

Both run on Firecracker microVMs. Unikraft Cloud turns a Dockerfile into a small VM that sleeps when idle and wakes on the next request, while Instabox gives an AI agent its own Linux computer with Docker, SSH and a desktop, free during an invite-only beta.

The companies and products

Unikraft Cloud

Unikraft Cloud is a microVM cloud from Unikraft Inc. that runs any Dockerfile-based workload as a minimal Linux microVM with millisecond cold starts and scale-to-zero.

Your Dockerfile becomes the VM image at build time, and each instance runs on a heavily customized Firecracker VMM, so it boots in milliseconds and can go into standby when no traffic arrives. It is a general compute platform built for dense, bursty work such as HTTP services, headless browsers and agent fleets, sold as flat self-serve plans plus Enterprise dedicated hosts, on-prem and bring your own cloud. It is not a dev machine you log into: instances are reached through services, the CLI and a sandbox plugin for commands and files.

Isolation: Linux microVM per instance on a customized Firecracker VMM; full VMs on Enterprise
Plans: Hobby free, Team $39/mo, Pro $199/mo, Enterprise custom; each caps running instances, vCPUs and memory
Running capacity: 2 / 8 / 24 running instances with 4 / 8 / 32 GiB memory in total on Hobby / Team / Pro
Regions: Dallas, Frankfurt, San Francisco, Singapore and Washington DC by default; more metros on request
Self-hosting: Dedicated host fleet, on-prem and BYOC on Enterprise
Compliance: SOC2, HIPAA and audit logs listed on Enterprise
Open source: The unikraft CLI is open source; the cloud platform is commercial

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
Machine size: 4 vCPUs and 8 GiB of memory, the same for every machine; 20 GB storage
Machines per account: 5, in any state: paused and stopped ones count
Price: Free during the beta; no published price yet
Access: Invite-only beta; sign in with GitHub or Google
Regions: Not published; more regions are on the roadmap as an idea
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. “2nd cheapest of 367” means 1 of the other 366 providers runs 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	Unikraft Cloud: 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 Docker and test suites inside the machine: Instabox runs Docker inside, Unikraft documents no container runtime inside, and boat adds /dev/kvm and sizes up to 16 vCPU / 32 GB.	Can't run it	No published price	3rd cheapest of 367 $634 a month
Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An agent that lives on its machine all month fits one Instabox machine, but Unikraft's Team pool is 8 GiB shared by every running instance.	Can't run it	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	Can't run it	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 Instabox allows 5 machines per account and Unikraft Pro runs 24 instances at once, so hundreds of active users need more than either offers today.	Can't run it	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	Can't run it	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 Instabox's 5-machine cap and Unikraft's 24-instance Pro pool limit how many evals run at the same time.	Can't run it	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 jobs that run Android emulators need /dev/kvm: boat exposes it, Unikraft keeps nested virtualization for Enterprise, and Instabox does not document it.	Can't run it	No published price	4th cheapest of 377 $86 a month
24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Instabox gives you SSH and mosh into a box, while Unikraft has no SSH yet and works through its CLI and sandbox plugin.	219th of 368, with limits $39 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 Instabox has a Linux desktop with a screenshot and click API, Unikraft has none built in, and boat streams its desktop at 60fps.	Can't run it	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 teams run their own headless Chrome on Unikraft; Instabox has a browser template, and boat gives each sandbox Chromium on a desktop.	Can't run it	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	Can't run it	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	Can't run it	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	Can't run it	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	Unikraft Cloud	Instabox	boat
Isolation	Minimal Linux microVM on a customized Firecracker VMM	Firecracker microVM with its own kernel and root	Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts
Machine size	Plan pool shared by all running instances: 2 vCPU / 4 GiB, 8 vCPU / 8 GiB or 24 vCPU / 32 GiB	One size for everyone: 4 vCPU / 8 GiB with 20 GB storage	4 vCPU / 8 GB by default, up to 16 vCPU / 32 GB per sandbox on the $100 plan and above
How many at once	2, 8 or 24 running instances by plan, more on Enterprise; sleeping ones do not count	5 machines per account, paused and stopped ones included	100 to 2,000 sandboxes at once on paid plans, with no session cap
Docker inside	The Dockerfile becomes the VM image; no container runtime inside is documented	Docker and Docker Compose run inside	Docker and Compose run inside, with root and systemd
Nested virtualization	Yes, with a per-instance flag and permission, Enterprise only	Not documented	Yes, /dev/kvm for Android emulators and VMs on every plan
SSH	Not yet; commands and files go through the sandbox plugin and CLI	SSH through a gateway with short-lived certificates, paste-anywhere SSH tokens and mosh	SSH into every sandbox
Desktop and computer use	None built in; you can run your own headless browser from a Dockerfile	Linux desktop with a browser on one template, screenshot and click API, shareable view or control links; you bring the model	Linux desktop streamed at 60fps, Chromium, and a computer-use agent
Idle and pause	Standby after a 1 second idle cooldown by default; stateful mode snapshots memory and resumes with warm caches	Pause keeps memory and running programs and usually resumes in about a second; auto pause after 30 idle minutes	Disk saved every minute and on stop; a stopped sandbox costs nothing and boots again on start
Wake on request	Yes; incoming traffic wakes a sleeping instance in milliseconds	No; port URLs go offline while a machine is paused, and a visit does not wake it	No; a stopped sandbox is started by API
Fork and snapshots	Checkpoint memory and volumes of a running microVM, then start new instances from it	Fork copies a stopped machine only; up to 10 snapshots, and saving stops a running machine first unless the server allows a live save	Fork a running sandbox with its disk; disk saved every minute, plus named snapshots of running sandboxes
Inbound access	Services on its load balancer: HTTP on 80, HTTPS on 443, TLS-wrapped TCP on other ports; no public IP per instance	HTTPS on up to 16 ports, open to anyone with the URL	HTTPS URLs for up to 50 ports, token-protected by default; raw TCP
Keeping API keys out of the sandbox	Network shield can inject secrets into traffic, Enterprise only, limited access	Vault writes your secrets into each machine as environment variables or files	Credentials proxy: real keys never enter the sandbox, for model providers and any HTTPS API, on every plan
Coding agents	None preinstalled; you bring the agent in your own image	Templates and saved agent sign-ins in snapshots; you run the agent yourself	Seven agents preinstalled, with a prompt, steer and events API
Regions	Dallas, Frankfurt, San Francisco, Singapore and Washington DC; more metros on request	Not published	EU only (Germany, Finland, France)

Every feature Battleships tracks (43)

Feature	Unikraft Cloud	Instabox	boat
Full VM (own kernel)	Yes	Yes	Yes
Docker inside	No	Yes	Yes
Nested virtualization	Yes	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	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	No	Yes
Memory fork	Yes	No	No
Custom image (Docker or snapshot)	Yes	Yes	Yes
≥24 h sessions	Yes	Yes	Yes
Idle auto-stop	Yes	Yes	No
Wake on request	Yes	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	No	Not published	Yes
Agent harness API	No	Not published	Yes
MCP server	No	Not published	No
GPU	Yes	No	No
Windows	No	No	No
Arm64	Yes	Not published	No
Self-hosting	Yes	Not published	No
BYOC	Yes	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	Yes	Not published	No
SSO	No	No	No
SOC 2	Yes	Not published	No
HIPAA	Yes	Not published	No
EU data residency	Yes	Not published	Yes
Zero data retention	Not published	Not published	Yes

Performance

Unikraft CloudNot measured

InstaboxNot measured

boat26.69 runs/s

Neither Unikraft Cloud nor Instabox has a comparable CPU measurement, so this page makes no speed claim between them. boat did 26.69 runs per second on the hpc-sandbox-benchmarks Node.js build-and-test loop at 4 vCPU / 8 GB. Unikraft states cold starts under 10 ms and Instabox says you are in a new machine's shell in under a second; both are their own figures about start time, not CPU speed.

Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Unikraft Cloud 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	Unikraft Cloud, 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	$39 · Hobby	No published price	$20 · $20/mo
One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month	$39 · Hobby	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	Can't run it	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	Can't run it	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	Can't run it	No published price	$2,000 · $2000/mo · with limits

Unikraft Cloud: Unikraft charges a flat monthly fee for a pool of running capacity: free for 2 vCPU / 4 GiB, $39 for 8 vCPU / 8 GiB and $199 for 24 vCPU / 32 GiB, with sleeping instances not counted. It publishes no per-hour rate, so anything bigger is an Enterprise quote.

Instabox: Instabox is free during the beta, with 5 machines per user, and its pricing page says "Free until we figure it out". It publishes no price yet, so no bill can be compared.

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

Unikraft's limits are pools that every running instance shares: Team has 8 vCPU and 8 GiB in total, so one 4 vCPU / 8 GB agent fills it, and the 50-agent, user-sandbox and burst scenarios need Enterprise. Instabox allows 5 machines per account, paused and stopped ones included, every machine is 4 vCPU / 8 GiB, and an API exec call runs at most 10 minutes, with 4 at once. Instabox publishes no rate, so none of the scenarios can be priced on it yet. boat has no session cap on paid plans, but at 1,000 short jobs at once its $2,000 plan queues starts.

Scenario	Unikraft Cloud	Instabox	boat
One coding agent, workdays	flat pool: the tier is billed whether used or not disk beyond 0 GiB: price unknown egress price not published	no published per-resource rate	None that bite
One agent that never stops	flat pool: the tier is billed whether used or not disk beyond 0 GiB: price unknown egress price not published	no published per-resource rate	None that bite
50 agents in parallel	no pool tier with 200 vCPU / 400 GiB for 50 VMs no published per-resource rate	no published per-resource rate	None that bite
Sandboxes for your users	no pool tier with 600 vCPU / 1,200 GiB for 300 VMs no published per-resource rate	no published per-resource rate	None that bite
1,000 short jobs at once	no pool tier with 2,000 vCPU / 4,000 GiB for 1,000 VMs no published per-resource rate	no published per-resource rate	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)

Which one should you use?

Use Unikraft Cloud when

you run many small services or headless browsers that sleep most of the time and must wake in milliseconds, or need US or Asia regions.

Wakes in milliseconds. Best for many small services that sleep most of the time and must answer the next request in milliseconds.
Published plans with room to grow. Its paid plans run up to 24 instances at once, with Enterprise for more, where Instabox stops at 5 machines.
Regions in the US and Asia. Unikraft runs in Dallas, San Francisco, Washington DC and Singapore as well as Frankfurt.

Use Instabox when

you want to try up to 5 free 4 vCPU / 8 GiB agent machines with Docker, SSH, mosh and a desktop during its beta.

Free during the beta. During the invite-only beta, every account can run 5 machines of 4 vCPU / 8 GiB for free.
A computer the agent works in. Each machine runs Docker inside and has a desktop with a screenshot and click API for computer use.
SSH gateway with mosh. SSH works out of the box, and mosh keeps a terminal session alive through sleep and network changes.

Where boat fits

If what you are running is coding agents, look at boat. Unikraft Cloud is built for small services that sleep and wake, and Instabox is a free beta with one machine size and 5 machines per account. boat gives each agent a full VM in sizes up to 16 vCPU / 32 GB, with published plans and fleets of 100 or more from the first paid plan.

A whole machine with Docker and /dev/kvm

Agents start databases with Docker and run Android emulators. Unikraft documents no container runtime inside and keeps nested virtualization for Enterprise, and Instabox does not document /dev/kvm, so emulators and VMs inside may not run there.

Real keys never enter the machine

Instabox's vault writes your secrets into each machine, where the agent can read them. Unikraft can inject secrets only through its network shield, which is Enterprise only and in limited access. boat's credentials proxy keeps keys outside on every plan.

Fleets of full-size machines

Fifty agents at 4 vCPU / 8 GB fit neither: Instabox stops at 5 machines, stopped ones included, and Unikraft's biggest self-serve pool is 24 vCPU / 32 GiB, so the rest is an Enterprise contract.

Use boat when your agents need a real machine to work in: Docker and /dev/kvm, bigger sizes, forks of running work, keys kept outside, coding agents you drive from outside, and fleets of more than a few machines. Compare it one to one: boat vs Unikraft Cloud and boat vs Instabox.

Questions people ask

Is Unikraft Cloud cheaper than Instabox?

It can't be compared yet. Instabox is free during its beta and publishes no price, so there is no bill to set against Unikraft's. Unikraft has a free Hobby plan and flat paid plans: Team at $39 and Pro at $199.

Which is faster, Unikraft Cloud or Instabox?

Neither has a comparable CPU measurement. Unikraft states cold starts under 10 ms, and Instabox says you are in a new machine's shell in under a second; its docs say a paused machine usually resumes in about a second. None of these figures has been measured here.

Can I run Docker inside Unikraft Cloud or Instabox?

On Instabox, yes: Docker and Docker Compose run inside each machine. Unikraft uses your Dockerfile to build the VM itself and does not describe a container runtime inside a running instance. A boat sandbox runs Docker with root and systemd.

Can I SSH into Unikraft Cloud or Instabox?

Instabox yes, through an SSH gateway with short-lived certificates, and it also relays mosh. Unikraft not yet: you run commands and move files through its sandbox plugin and CLI. boat gives SSH into every sandbox.

Can I run Android emulators on them?

Emulators need nested virtualization. Unikraft offers it on Enterprise only, with a per-instance flag, and Instabox's docs do not mention it. boat exposes /dev/kvm on every plan.

Can anyone sign up for Instabox?

Not yet. Instabox launched on 2026-10-14 as an invite-only beta, with sign-in through GitHub or Google. Unikraft Cloud has a self-serve free plan.

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