Azure Container Apps Sandboxes vs Instabox
Both give each agent a microVM with its own kernel that can pause with its memory. Azure is a headless service inside your Azure account with many sizes and 40 regions, while Instabox is a new invite-only beta with SSH, a desktop and one free machine size.
The companies and products
Azure Container Apps Sandboxes
Azure Container Apps Sandboxes is a service inside Microsoft Azure that gives each agent or user an isolated microVM you create, suspend and resume through an SDK.
It is part of Azure Container Apps, the hyperscaler's serverless container platform, and lives in your Azure subscription as a sandbox group resource. Each sandbox boots from an OCI image or a snapshot, has its own kernel, and can be suspended with its memory and resumed in under a second. It is built for teams already on Azure that want stateful code execution with Azure networking, identity and billing.
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. “34th cheapest of 345” means 33 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 | Azure Container Apps 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 Long builds need Docker and room to grow: Azure's Docker depends on the image, Instabox has one 4 vCPU / 8 GiB size, and boat goes up to 16 vCPU / 32 GB. | 288th of 367, with limits $5,276 a month | No published price | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB | 302nd of 366, with limits $6,544 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 Azure fits short code runs well, since a sandbox suspends with its memory and wakes on traffic; Instabox has no published price to rank it on. | 34th cheapest of 345 $354 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 Azure can give a sandbox to each of many users; Instabox allows 5 machines per account, paused and stopped ones included, so it cannot yet. | 22nd cheapest of 361 $2,260 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 | 153rd of 360, with limits $10,740 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 Instabox's 5-machine cap limits how many evals run at once, while Azure starts with 500 active cores and boat sets concurrency by plan. | 75th cheapest of 364 $1,728 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 Azure nor Instabox documents. | 103rd cheapest of 377 $1,046 a month | No published price | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Instabox gives SSH with mosh, and Azure gives a shell only through its CLI, SDK or portal; boat has SSH on every sandbox. | 322nd of 368, with limits $262 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 Azure's sandboxes are headless; Instabox has a desktop with a browser on one template, and boat streams a desktop at 60fps in every sandbox. | 279th of 369, with limits $1,573 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 Instabox has a browser on one desktop template, on Azure you install one in your own image, and boat ships Chromium in every sandbox. | 288th of 367, with limits $795 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 | 284th of 346, with limits $561 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 | 239th of 338, with limits $10,956 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 | 278th of 360, with limits $517 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 | Azure Container Apps Sandboxes | Instabox | boat |
|---|---|---|---|
| Isolation | MicroVM per sandbox with its own kernel | Firecracker microVM with its own kernel and root | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Machine sizes | Tiers from 0.25 cores / 0.5 GB to 4 cores / 8 GB; up to 16 vCPU / 32 GB by API | One size for everyone: 4 vCPU / 8 GiB with 20 GB storage | Several sizes, up to 8 vCPU / 16 GB on the $20 plan and 16 vCPU / 32 GB on $100 and above |
| How many at once | 500 concurrent active cores by default; more by support request, which can need review | 5 machines per account, paused and stopped ones included | Concurrency set by plan, up to 2,000 sandboxes, self-serve |
| Docker | Depends on the image: azure-dev ships Docker; the default ubuntu image has only Buildah | Docker and Docker Compose run inside | Docker, systemd and root on every sandbox |
| Nested virtualization | Not documented | Not documented | Yes, /dev/kvm for Android emulators and VMs |
| Getting a shell | Interactive shell through the aca CLI, SDK or portal; no SSH | SSH through a gateway with short-lived certificates, SSH tokens and mosh | SSH, plus CLI and API exec |
| Desktop and computer use | Headless; no desktop or managed browser | Linux desktop with a browser on one template, screenshot and click API, shareable view or control links | 60fps Linux desktop with Chromium and computer-use tools in every sandbox |
| Pause with memory | Suspends with memory and disk; resumes in under a second, and network traffic wakes it | Pause keeps memory and running programs; resume usually takes about a second; a visit does not wake it | Stop keeps the disk, saved every minute; start boots the machine again |
| Fork and snapshots | Snapshot a running sandbox with its memory and create new sandboxes 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 and on stop |
| Public port URLs | Public HTTPS routes per published port; private endpoint from your VNet at extra cost; no public IP | 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; dedicated IPv4 or IPv6 |
| Outbound rules | Egress policy with allow, deny, rewrite and header rules by host, path and method; VNet integration | Not documented | Open internet, no provider-side allowlist |
| Keeping API keys out of the sandbox | Group secrets usable in egress header transforms; Copilot and Anthropic tokens are injected into the sandbox at startup | Vault writes your secrets into each machine as environment variables or files | Credentials proxy: real model keys and any HTTPS API key stay outside; switch a credential to another account when credits run out |
| Coding agents | Copilot CLI and Claude Code images, run through the exec API | Templates and saved agent sign-ins in snapshots; you run the agent yourself | Seven agents preinstalled, with a prompt, steer and events API |
| Regions | 40 Azure regions, 9 of them in the EU | Not published | EU only (Germany, Finland, France) |
Every feature Battleships tracks (43)
| Feature | Azure Container Apps 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 | Yes | 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 | No | 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 | No | Not published | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | No | 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 | Yes | Not published | Yes |
| Usage per sandbox (API) | Yes | Yes | Yes |
| Audit logs | Yes | Not published | No |
| SSO | Yes | 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
Neither Azure Container Apps Sandboxes nor Instabox has a comparable CPU measurement yet, so this page makes no speed claim between them. boat did 26.69 runs per second on the StarSling hpc-sandbox-benchmarks Node.js build-and-test loop at 4 vCPU / 8 GB. 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. Azure Container Apps 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 | Azure Container Apps 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 | $68 · 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 | $262 · 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 | $3,421 · Pay-as-you-go | 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 | $989 · Pay-as-you-go | 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 | $2,148 · Pay-as-you-go | No published price | $2,000 · $2000/mo · with limits |
Azure Container Apps Sandboxes: Azure bills per second on the Container Apps Consumption meters for the vCPU and memory of the sandbox's tier, idle time before auto-suspend included. There is no plan fee, stopped sandboxes pay no CPU or memory, and some regions charge more.
Instabox: Instabox is free during the beta, with 5 machines per user, and publishes no price yet, so no bill can be compared with Azure'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
Instabox allows 5 machines per account, paused and stopped ones included, all 4 vCPU / 8 GiB, so the 50-agent, user-sandbox and burst scenarios do not fit it, and with no published rate none of them can be priced. Azure has no session cap, but it bills a running sandbox until it suspends, so the always-on scenario only gets close with a 3-year commitment, and its default quota of 500 active cores caps a fleet until support raises it. boat's start limits are the tight ones for 1,000 short jobs at once: the $2,000 plan queues starts, while Azure handles that burst.
| Scenario | Azure Container Apps 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 |
| 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 Azure Container Apps Sandboxes when
your team already runs on Azure and wants short stateful sandboxes that suspend with their memory, wake on traffic, sit behind egress rules, or run in many regions.
- Memory suspend and wake on traffic. For stateful jobs that sleep between requests, a sandbox suspends with its memory and network traffic wakes it in under a second.
- Outbound rules and Azure networks. Teams that must limit where an agent connects get egress rules by host, path and method, and can join their Azure VNets.
- Sizes, scale and regions. Teams already on Azure get sizes from 0.25 cores to 16 vCPU, 500 active cores to start, and 40 regions.
Use Instabox when
you have an invite and want to try a few free 4 vCPU / 8 GiB agent machines with SSH, mosh and a desktop during its beta.
- Free to try during the beta. If you have an invite, you can run 5 machines of 4 vCPU / 8 GiB for free while the beta lasts.
- SSH with mosh. Developers who live in a terminal get an SSH gateway with mosh and paste-anywhere SSH tokens, which Azure does not offer.
- A desktop you can share. For computer-use tests, one template has a Linux desktop with a browser, a click API and shareable view or control links.
Where boat fits
If your agents do real engineering work, both Azure and Instabox leave gaps. Neither documents /dev/kvm, both put API keys inside the machine, and both cap a fleet: Instabox at 5 machines, Azure at a default core quota. boat gives every agent a full VM with SSH, Docker, a 60fps desktop and a credentials proxy, on published plans.
Emulators and VMs inside the sandbox
Neither Azure nor Instabox documents nested virtualization, so an agent that needs an Android emulator or builds a VM image may not run there at all. boat exposes /dev/kvm on every sandbox.
A fleet that grows when you need it
Instabox stops at 5 machines of one size, and Azure starts at 500 active cores, with more only by a support request that can need review. boat sets concurrency by plan, up to 2,000 sandboxes, self-serve.
Real keys stay outside
Azure injects Copilot and Anthropic tokens into the sandbox, and Instabox's vault writes secrets into the machine, where a prompt-injected agent can read them. boat's credentials proxy keeps real keys outside for any HTTPS API.
Use boat when your agents need a whole computer for real work: SSH, Docker, /dev/kvm, a 60fps desktop and a browser, with coding agents and a credentials proxy built in, at fleet sizes you set yourself. Compare it one to one: boat vs Azure Container Apps Sandboxes and boat vs Instabox.
Questions people ask
Is Azure Container Apps Sandboxes cheaper than Instabox?
It can't be compared yet. Instabox is free during the beta, with 5 machines per user, and has no published price. Azure bills per second; one coding agent on workdays comes to $68 a month there, against $20 on boat.
Which is faster, Azure Container Apps Sandboxes or Instabox?
Neither has a comparable CPU measurement, so there is no answer yet. Azure documents resume from suspend in under a second, and Instabox's docs say a paused machine usually resumes in about a second. Instabox says a new machine's shell is ready in under a second, which has not been measured here.
Can I SSH into Azure Container Apps Sandboxes or Instabox?
Instabox, yes: it runs SSH through a gateway with short-lived certificates and also relays mosh. Azure, no: you get a shell through the aca CLI, the SDK or the portal. boat has SSH on every sandbox.
Can they run Docker and Android emulators?
Instabox runs Docker and Docker Compose inside. On Azure it depends on the image: azure-dev ships Docker, while the default ubuntu image has only Buildah. Neither documents nested virtualization, which boat offers through /dev/kvm.
Can I fork a running sandbox?
On Azure, yes: you snapshot a running sandbox with its memory and create new ones from it. Instabox's fork copies a stopped machine only. boat forks a running sandbox with its disk while the original keeps working.
Is boat SOC 2 compliant?
SOC 2 is in progress. We're open about where we stand: live status at status.ascii.dev and our data retention policy at docs.boat.dev/data-retention.
Try boat
Install the CLI, then run boat new.
7-day free trial
More comparisons
- boat vs Azure Container Apps Sandboxes
- boat vs Instabox
- E2B vs Azure Container Apps Sandboxes
- Daytona vs Azure Container Apps Sandboxes
- Modal vs Azure Container Apps Sandboxes
- Vercel Sandbox vs Azure Container Apps Sandboxes
- Cloudflare Sandbox vs Azure Container Apps Sandboxes
- Blaxel vs Azure Container Apps Sandboxes
- Runloop vs Azure Container Apps Sandboxes
- Tensorlake vs Azure Container Apps Sandboxes
- Morph Cloud vs Azure Container Apps Sandboxes
- CodeSandbox SDK vs Azure Container Apps Sandboxes