GitHub Codespaces vs Deno Sandbox

GitHub Codespaces is a cloud dev environment: a dev container for a GitHub repository that a person opens in VS Code and that stops after 12 hours at most. Deno Sandbox is a sandbox API: a small Firecracker microVM that starts in under 200 ms, runs locked-down code for up to 30 minutes, then wipes its disk.

The companies and products

GitHub Codespaces

GitHub Codespaces is GitHub's cloud development environment: a ready-to-code Linux machine for a repository, opened in the browser, VS Code or the GitHub CLI.

Codespaces is a different kind of product from boat: a dev environment for people working on a GitHub repository, not a sandbox API for agents. Each codespace is a Docker container built from the repo's dev container config, running on its own newly built VM on Azure, with 2 to 32 cores. It is built for developers and teams who want every contributor to start from the same setup, with prebuilds, port forwarding and GitHub billing.

Isolation: A Docker container on its own newly built VM, with its own virtual network
Operating system: Linux only; Windows and macOS are not supported for the remote container
Machine sizes: 2, 4, 8, 16 or 32 cores, with 4 GB of memory per core
Lifetime: Stops after 30 idle minutes by default (5 to 240), and after 12 hours at most even while in use
Regions: US East, US West, Europe West and Southeast Asia
Free usage: Personal Free accounts get 120 core-hours and 15 GB-month a month, Pro 180 and 20; organizations get no free quota
Compliance: GitHub Enterprise Cloud lists SOC 1, SOC 2 and SOC 3 reports and ISO 27001

Deno Sandbox

Deno Sandbox is part of Deno Deploy, the hosting platform from the company behind the Deno runtime, and runs untrusted or AI-generated code in Linux microVMs.

Each sandbox is a Firecracker microVM with 2 vCPU, up to 4 GB of memory and a 10 GB disk that is wiped when it ends, created from a TypeScript or Python SDK. Outbound traffic goes through a proxy that can enforce a host allowlist and swap placeholder secrets for real ones. It is built for short runs of agent or user code, and a sandbox can be promoted to a Deno Deploy app.

Isolation: Firecracker microVM per sandbox
Machine size: 2 vCPU, 768 MB to 4 GB memory, 10 GB ephemeral disk
Lifetime: Bound to a session, up to 30 minutes
Regions: Amsterdam and Chicago; volumes only in Chicago
Plans: Sandboxes on Pro and Builder; 3 or 20 at once per region
Compliance: Deno Deploy states SOC2 and ISO27001; HIPAA BAA for enterprise contracts

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. “274th cheapest of 367” means 273 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	GitHub Codespaces: price rank	Deno Sandbox: price rank	boat: price rank
Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Codespaces runs Docker in a dev container but stops at 12 hours, and Deno caps a sandbox at 30 minutes and 2 vCPU, while boat is a full VM that keeps running.	274th of 367, with limits $4,618 a month	290th of 367, with limits $5,665 a month	3rd cheapest of 367 $634 a month
Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Neither suits an assistant that lives on its machine all month: a codespace stops after 12 hours and a Deno sandbox after 30 minutes with its disk wiped.	309th of 366, with limits $6,970 a month	287th of 366, with limits $5,803 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 Deno Sandbox fits short code runs best of the two: it starts in under 200 ms and bills CPU only while code runs, while each codespace builds a dev container on a new VM.	288th of 345, with limits $619 a month	141st of 345, with limits $329 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 Deno allows 20 sandboxes at once per region on Builder and GitHub does not publish its limit, while boat's plans go to hundreds of sandboxes.	281st of 361, with limits $1,964 a month	148th of 361, with limits $1,863 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	282nd of 360, with limits $9,489 a month	122nd of 360, with limits $7,963 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	295th of 364, with limits $1,519 a month	296th of 364, with limits $1,563 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 Codespaces runs Docker but documents no /dev/kvm, Deno documents neither, and neither can fork a warm machine, while boat has Docker, /dev/kvm and fork.	314th of 377, with limits $909 a month	304th of 377, with limits $731 a month	4th cheapest of 377 $86 a month
24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Codespaces is the stronger dev box of the two, a polished VS Code setup per repo, but it still stops after 12 hours, while boat keeps running.	130th of 368, with limits $270 a month	179th of 368, with limits $200 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 graphical desktop; boat streams a 60fps Linux desktop with Chromium for computer use.	267th of 369, with limits $1,367 a month	280th of 369, with limits $1,583 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	275th of 367, with limits $678 a month	284th of 367, with limits $783 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	310th of 346, with limits $922 a month	286th of 346, with limits $573 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	280th of 338, with limits $18,637 a month	247th of 338, with limits $11,923 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 Codespaces creates every copy again from the repository and Deno boots copies from a read-only volume snapshot, while boat forks one prepared machine while it runs.	267th of 360, with limits $445 a month	251st of 360, with limits $367 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	GitHub Codespaces	Deno Sandbox	boat
What it is	A cloud dev environment for a GitHub repository, opened in VS Code, the browser or the GitHub CLI	A sandbox API in Deno Deploy for running untrusted or AI-generated code	A sandbox you drive from code: full VMs with a desktop and coding agents built in
Isolation	A Docker container on its own newly built VM, with its own virtual network	Firecracker microVM with its own kernel	Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts
Machine size	2, 4, 8, 16 or 32 cores, with 4 GB of memory per core	2 vCPU fixed, 768 MB to 4 GB memory, 10 GB disk	4 vCPU / 8 GB by default, up to 16 vCPU / 32 GB on the $100 plan and above
How long it runs	Stops after 30 idle minutes by default (up to 240) and after 12 hours at most, even while in use	Up to 30 minutes; longer work can be promoted to a Deno Deploy app	Runs until you stop it; no session cap on paid plans
Files after a stop	Saved files are kept and storage is billed; stopped codespaces are deleted after 30 days by default	Root disk wiped when the sandbox ends; opt-in volumes of 300 MB to 20 GB, Chicago only	The whole disk is kept, saved every minute and on stop; a stopped sandbox costs nothing
Fork and snapshots	No copy or snapshot endpoint; new codespaces start from a repo, branch, pull request or prebuild	Read-only snapshots of a volume that many new sandboxes can boot from; no fork of a running sandbox	Fork a running sandbox into copies with its files; named snapshots as templates
Docker and nested virtualization	Docker and sudo inside the dev container; /dev/kvm not documented	Root access; Docker and nested virtualization not documented	Docker, root, systemd and /dev/kvm on every machine
Desktop and editor	VS Code in the browser or on your machine, JupyterLab and a terminal; no graphical desktop	A VS Code editor in the browser and SSH; no desktop	60fps Linux desktop with Chromium, computer use and browser control
Coding agents	GitHub Copilot as a VS Code extension; other agents you install yourself	A root image with Claude Code, run through the shell command API	Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API
Keeping keys out of the sandbox	Secrets are copied into the codespace as environment variables	Secrets swapped in on outbound requests to approved hosts; the sandbox only sees a placeholder	Credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out
Outbound rules	Open internet; GitHub says there is no way to restrict it	Host allowlist per sandbox (allowNet), enforced by a proxy outside the VM	Open internet, no provider-side allowlist
Reaching the sandbox	A URL per forwarded port, private, organization or public; SSH; no public IP	HTTPS URL per exposed port, public without authentication; SSH	HTTPS URLs for up to 50 ports, token-protected by default; raw TCP
Start time	Builds a dev container on a new VM; prebuilds speed it up	Under 200 ms	Boots a full VM
Regions	US East, US West, Europe West and Southeast Asia	Amsterdam and Chicago	EU only: Germany, Finland, France

Every feature Battleships tracks (43)

Feature	GitHub Codespaces	Deno Sandbox	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	No	Yes
Computer-use API	No	No	Yes
SSH	Yes	Yes	Yes
Persistent disk	Yes	Yes	Yes
Pause/resume	Yes	No	Yes
Automatic snapshots	No	No	Yes
Fork/clone	No	No	Yes
Live fork (no pause)	No	No	Yes
Memory fork	No	No	No
Custom image (Docker or snapshot)	Yes	Yes	Yes
≥24 h sessions	No	No	Yes
Idle auto-stop	Yes	No	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	No	Yes	No
Secret proxy	No	Yes	Yes
Secret proxy for any API	No	Yes	Yes
Preinstalled agents	No	Yes	Yes
Agent harness API	No	No	Yes
MCP server	No	No	No
GPU	No	No	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	Not published	Yes
Spend limits	Yes	Yes	Yes
Usage per sandbox (API)	No	No	Yes
Audit logs	Yes	Not published	No
SSO	Yes	No	No
SOC 2	Yes	Yes	No
HIPAA	No	Yes	No
EU data residency	Yes	Yes	Yes
Zero data retention	Not published	Not published	Yes

Performance

GitHub CodespacesNot measured

Deno SandboxNot measured

boat26.69 runs/s

There is no comparable measurement for GitHub Codespaces or Deno Sandbox: neither was in the public benchmark runs we use, and Deno's fixed 2 vCPU shape could not run the 4 vCPU test as set up. boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB in StarSling's run of 2026-09-29, on dedicated AMD Ryzen 9 9950X hosts.

Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. GitHub Codespaces and Deno Sandbox 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	GitHub Codespaces, a month	Deno Sandbox, 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	$51 · Personal account: GitHub Free	$53 · Pro · with limits	$20 · $20/mo
One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month	$270 · Personal account: GitHub Free · with limits	$200 · Builder · 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	$3,019 · Personal account: GitHub Free	$2,779 · Builder · 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	$850 · Personal account: GitHub Free · with limits	$783 · Builder · 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	$1,889 · Personal account: GitHub Free · with limits	$1,563 · Builder · with limits	$2,000 · $2000/mo · with limits

GitHub Codespaces: Codespaces bills $0.09 per core-hour for the whole time a codespace is active, plus $0.07 per GB-month of storage while it exists, stopped too. Personal accounts get a free monthly quota and organizations do not.

Deno Sandbox: Sandboxes need the Pro plan at $20 a month or Builder at $200 a month, which include allowances shared with Deno Deploy apps. Past those, CPU costs $0.10 per hour of active CPU time and memory $0.025 per GiB-hour for the whole life of the sandbox.

Deno Sandbox: Plans start at $20 a month, and the whole fee is usage credit spent per second while a sandbox runs. A stopped sandbox costs nothing and keeps its disk.

Limits in those scenarios

Deno Sandbox fits none of the five scenarios as written: a sandbox lives up to 30 minutes, is fixed at 2 vCPU with up to 4 GB, and Builder allows 20 at once per region. Codespaces fits the workday agent at $51 a month and likely 50 agents at $3,019, but stops every 12 hours, so the always-on agent needs a restart script, and GitHub does not publish how many can run at once for 300 user sandboxes or 1,000 short jobs. boat fits four of the five; at 1,000 short jobs at once its top plan queues starts above 90 a minute, so none of the three fits that one without a custom plan.

Scenario	GitHub Codespaces	Deno Sandbox	boat
One coding agent, workdays	None that bite	Pro: sessions capped at 0.5 h capped at 2 vCPU / 4 GiB largest size is 2 vCPU / 4 GiB disk beyond 10 GiB: price unknown	None that bite
One agent that never stops	Personal account: GitHub Free: sessions capped at 12 h	Builder: sessions capped at 0.5 h capped at 2 vCPU / 4 GiB largest size is 2 vCPU / 4 GiB disk beyond 10 GiB: price unknown	None that bite
50 agents in parallel	how many machines can run at once: limit not published, probably fine at 50 (the typical published limit is 50)	Builder: max 20 concurrent Builder: sessions capped at 0.5 h capped at 2 vCPU / 4 GiB largest size is 2 vCPU / 4 GiB	None that bite
Sandboxes for your users	not confirmed: how many machines can run at once (you need 300; the typical published limit is 50)	Builder: max 20 concurrent	None that bite
1,000 short jobs at once	not confirmed: how many machines can run at once (you need 1,000; the typical published limit is 50)	Builder: max 20 concurrent	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 GitHub Codespaces when

your developers want a ready VS Code environment for a GitHub repository, opened from a branch or pull request, on a machine of up to 32 cores, in the US, EU or Asia.

Built into GitHub. Useful if your team lives on GitHub: open a codespace from any repo, branch or pull request, with the dev container already set up.
Bigger machines and longer sessions. Useful for heavy builds: machines go up to 32 cores and run up to 12 hours, against 2 vCPU and 30 minutes on Deno.
Free hours for personal accounts. Useful for occasional personal work: a GitHub Free account includes 120 core-hours and 15 GB-month of storage each month.

Use Deno Sandbox when

you run short pieces of untrusted code that must start in milliseconds and reach only the hosts you allow, especially if you already deploy on Deno Deploy.

Locked-down outbound traffic. Useful for running untrusted code: each sandbox can be limited to a list of hosts, enforced by a proxy outside the VM.
Fast starts and active-CPU billing. Good for short bursts of code: a sandbox starts in under 200 ms and CPU bills only while code runs.
Keys kept outside the sandbox. Useful when agent code calls paid APIs: the sandbox sees only a placeholder, swapped for the real secret on approved hosts.

Where boat fits

If what you are really running is coding agents, both products make you work around a clock: Codespaces stops at 12 hours and Deno at 30 minutes. boat gives each agent a full VM that keeps running, keeps its disk and forks while it runs, with agents, a desktop and open ports built in.

No session clock

A long agent task is stopped at 12 hours on Codespaces and at 30 minutes on Deno, so you write code to restart it and resume. A boat sandbox runs until you stop it, with no session cap on paid plans.

A full machine that keeps its work

Deno wipes the root disk and is fixed at 2 vCPU and 4 GB; Codespaces keeps files but documents no /dev/kvm and has no fork. boat has Docker, systemd and /dev/kvm, saves the disk every minute, and forks a running sandbox.

Agents and a desktop you drive from outside

On both you start and watch each agent through shell commands, and neither has a desktop for computer use. boat ships Claude Code, Codex and more with a prompt, steer and events API, plus a 60fps desktop with Chromium.

Use boat when your code starts and drives agents that work for hours or days: full VMs with Docker, /dev/kvm and a desktop, built-in coding agents with keys kept outside, and machines that keep their work and fork while running. Compare it one to one: boat vs GitHub Codespaces and boat vs Deno Sandbox.

Questions people ask

Is GitHub Codespaces cheaper than Deno Sandbox?

It depends on the job, and they bill differently. For one coding agent on workdays Codespaces comes to $51 a month and Deno $53, but Deno does not fit at 30 minutes and 2 vCPU. For 300 user sandboxes Codespaces is $850 and Deno $783, and boat is $200.

Which is faster, GitHub Codespaces or Deno Sandbox?

Neither has a comparable CPU measurement in the benchmark we use. Deno says a sandbox starts in under 200 ms, while a codespace builds a dev container on a new VM, which prebuilds speed up. boat did 26.69 runs per second on that benchmark at 4 vCPU / 8 GB.

Can GitHub Codespaces or Deno Sandbox run Docker?

Docker works inside a codespace through dev container features, with sudo, but GitHub does not document /dev/kvm. Deno's docs give root access but do not say Docker or nested virtualization works. Every boat machine has Docker, systemd and /dev/kvm.

How long can a codespace or a Deno sandbox run?

A codespace stops after 30 idle minutes by default and after 12 hours at most, even while in use. A Deno sandbox lives up to 30 minutes and its root disk is wiped when it ends. A boat sandbox runs until you stop it, with no session cap on paid plans.

Can I run Claude Code in either?

Yes. In Codespaces you install it yourself, with your API key as a secret that arrives as an environment variable. Deno has a root image with Claude Code that you run through shell commands, and swaps in real keys only on approved hosts. boat ships it preinstalled with an API to prompt, steer and watch it.

Where do they run?

Codespaces runs in US East, US West, Europe West and Southeast Asia. Deno Sandbox runs in Amsterdam and Chicago, with volumes only in Chicago. boat runs only in the EU, in Germany, Finland and France.

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