E2B vs Deno Sandbox
Both run code in Firecracker microVMs. E2B gives each sandbox up to 8 vCPU and 24-hour sessions it can pause with memory, while Deno Sandbox runs short, locked-down 2 vCPU jobs that start in under 200 ms and end after 30 minutes.
The companies and products
E2B
E2B calls itself the AI agent cloud: an API that gives each agent session its own isolated Linux machine.
Every E2B sandbox is a Firecracker microVM that boots from a snapshot, so it starts fast and can be paused and resumed with its memory. You build custom sandboxes from templates based on a Docker image, and drive them from Python or JavaScript SDKs. It is built for teams that run many short code, data or agent jobs, and its runtime is open source.
- Isolation
- Firecracker microVM per sandbox
- Bring your own cloud
- Enterprise data plane in your AWS, GCP or Azure account
- Compliance
- SOC 2 Type II; HIPAA BAA on request
- Machine size
- 1 to 8 vCPU and 1 to 8 GiB RAM, CPU only
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
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. “16th cheapest of 367” means 15 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 | E2B: 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 A software factory runs installs and builds for hours, which fits E2B's 24-hour sessions but not Deno's 30-minute, 2 vCPU sandboxes; boat adds no session cap and /dev/kvm. | 16th cheapest of 367 $4,143 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 An assistant that lives on its machine all month outlasts both: E2B has to pause and resume every 24 hours, and a Deno sandbox ends after 30 minutes. | 51st of 366, with limits $5,348 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 Both suit short code runs: E2B pauses with memory and wakes on the next request, while Deno starts in under 200 ms and bills CPU only while code runs. | 37th cheapest of 345 $421 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 E2B's Pro+ plan allows 600 sandboxes at once, while Deno Builder allows 20 per region; boat gives each user a bigger machine with token-protected hosting. | 23rd cheapest of 361 $2,354 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 E2B's memory forks and high start rate suit many short rollouts that branch from the same state, which Deno Sandbox cannot fork. | 2nd cheapest of 360 $9,384 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 | 78th cheapest of 364 $1,975 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 CI jobs that build Android apps or VM images need nested virtualization, which neither E2B nor Deno Sandbox offers and boat does. | 337th of 377, with limits $1,429 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 A dev box that stays on all month needs no lifetime cap and a disk that persists, which is how boat works by default. | 192nd of 368, with limits $358 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 E2B has a Linux desktop for computer use and Deno Sandbox has none; boat streams its desktop at 60fps with Chromium built in. | 32nd cheapest of 369 $1,342 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 | 100th of 367, with limits $746 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 | 57th cheapest of 346 $554 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 | 227th of 338, with limits $9,223 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 | 11th cheapest of 360 $1,043 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 | E2B | Deno Sandbox | boat |
|---|---|---|---|
| Isolation | Firecracker microVM with its own kernel | Firecracker microVM with its own kernel | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Machine size | 1 to 8 vCPU and up to 8 GiB RAM self-serve; 20 GiB disk on Pro | 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 |
| Session length | Up to 1 hour on Hobby, 24 hours on Pro; pausing resets the clock | Up to 30 minutes; longer work can be promoted to a Deno Deploy app | No cap on paid plans; you set the time to live |
| Pause and resume | Saves memory and disk; resume takes about 1 second with processes still running | No pause; the root disk is wiped when the sandbox ends, opt-in volumes in Chicago only | Disk is saved every minute and on stop; resume boots the machine again |
| Fork | Fork a running sandbox with its memory, up to 20 copies per call | Read-only volume snapshots that new sandboxes boot from; no fork of a running sandbox | Fork a running sandbox with its disk |
| Wake on request | Yes; a paused sandbox can resume on the next HTTP request or SDK call | No | No; a stopped sandbox is started by API |
| Docker and nested virtualization | Docker inside; nested virtualization not supported | Root access; Docker and nested virtualization not documented | Docker, systemd and /dev/kvm for Android emulators and VMs |
| Desktop and computer use | Linux desktop for computer use | No desktop; a VS Code editor in the browser and SSH | Linux desktop streamed at 60fps, Chromium and computer use built in |
| Inbound access | HTTPS URL per port, public by default unless you turn on a token | HTTPS URL per exposed port, public without authentication; SSH | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP |
| Outbound rules | Allow and deny lists by IP, CIDR or domain | Host allowlist per sandbox, enforced by a proxy outside the VM | Open internet, no provider-side allowlist |
| Keeping API keys out of the sandbox | Secrets injected into outbound HTTPS headers (private beta) | Secrets swapped in on 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 |
| Coding agents | Templates and guides for many agents, run through the command API | A root image with Claude Code, run through the shell command API | Seven agents preinstalled, with a prompt, steer and events API |
| CPU benchmark (4 vCPU / 8 GB) | 12.61 runs/s | Not measured; the 2 vCPU shape cannot run the 4 vCPU test | 26.69 runs/s |
| Regions and self-hosting | US by default, EU and APAC on Pro and above; open-source runtime and bring your own cloud | Amsterdam and Chicago; no self-hosting | EU only (Germany, Finland, France); no self-hosting |
Every feature Battleships tracks (43)
| Feature | E2B | 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 | Yes | Not published | Yes |
| Desktop GUI | Yes | No | Yes |
| Browser | Yes | No | Yes |
| Computer-use API | Yes | No | Yes |
| SSH | Yes | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | No | Yes |
| Automatic snapshots | Yes | No | Yes |
| Fork/clone | Yes | No | 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 | No | Yes |
| Idle auto-stop | Yes | No | No |
| Wake on request | Yes | No | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | No | No | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | Yes | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | Yes | Yes | Yes |
| Preinstalled agents | Yes | Yes | Yes |
| Agent harness API | No | No | Yes |
| MCP server | Yes | No | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | No | No | No |
| Self-hosting | Yes | No | No |
| BYOC | Yes | No | No |
| Open source | Yes | 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 | Not published | No |
| SSO | No | No | 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
E2B and boat were measured in the same StarSling hpc-sandbox-benchmarks run, a Node.js build-and-test loop at 4 vCPU / 8 GB. boat did 26.69 runs per second and E2B did 12.61, so boat finished about twice the CPU work in the same time. Deno Sandbox has no comparable measurement, since its fixed 2 vCPU shape cannot run the 4 vCPU test.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Deno Sandbox 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 | E2B, 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 | $202 · Pro | $53 · Pro · with limits | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $368 · Pro · 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 | $2,773 · Pro | $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 | $1,395 · Pro+ (600 concurrent) | $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 | $2,797 · Pro++ (1,100 concurrent) | $1,563 · Builder · with limits | $2,000 · $2000/mo · with limits |
E2B: E2B bills per second for the vCPU and RAM you set, idle time included, until you pause or kill the sandbox. Pro costs $150 a month for higher limits with no usage credit, and more concurrency costs $500 a month per 500 slots.
Deno Sandbox: Sandboxes need the Pro plan at $20 a month or Builder at $200 a month, which include allowances shared with your 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. You pay per second while a sandbox runs, and 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 and 4 GB, and Builder allows 20 at once per region. E2B fits four of the five, but its 24-hour session cap on Pro rules out the agent that never stops, and Pro includes 20 GiB of disk. boat fits four of the five too; at 1,000 short jobs at once its top plan caps starts per hour and per day, while E2B Pro++ only queues bursts above 300 starts a minute.
| Scenario | E2B | Deno Sandbox | boat |
|---|---|---|---|
| One coding agent, workdays |
|
| 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 E2B when
you run many short or medium jobs that pause between requests, fork from the same state, or need more than 2 vCPU and more than 30 minutes.
- Memory pause, fork and wake on request. For jobs that sleep between requests: a paused sandbox resumes in about a second with its processes still running.
- Bigger machines and longer sessions. For builds and agent tasks past 30 minutes: up to 8 vCPU, 8 GiB and 24-hour sessions on Pro.
- Open source and more regions. For teams that want control: the runtime is Apache-2.0, and it runs in the US, EU and APAC.
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.
- Fast starts and active-CPU billing. For short bursts of code: a sandbox starts in under 200 ms and CPU bills only while code runs.
- Locked-down outbound traffic. For untrusted code: each sandbox reaches only the hosts you allow, and real secrets never enter the VM.
- A path to Deno Deploy. For teams already on Deno Deploy: a sandbox can be promoted to a Deploy app on the same meters.
Where boat fits
If your agents do real work for hours, both E2B and Deno Sandbox make you work around their session limits. boat gives each agent a full VM with no session cap, a disk that is still there tomorrow, Docker and /dev/kvm, and coding agents you drive from outside.
No session cap, and the disk stays
E2B stops a sandbox after 24 hours on Pro, so your code must pause and resume it. A Deno sandbox ends after 30 minutes and wipes its root disk. boat runs as long as you set and saves the disk every minute.
A fuller, faster machine
E2B does not support nested virtualization and Deno does not document Docker, so emulators and VM builds cannot start. Deno is fixed at 2 vCPU and 4 GB. boat did 26.69 runs/s on the CPU test against E2B's 12.61.
Agents and a desktop built in
On E2B and Deno you run Claude Code through a command API and parse its output yourself, and Deno has no desktop. boat ships seven agents with a prompt, steer and events API, plus a 60fps desktop with Chromium.
Use boat when your agents do real work for hours: installs, builds, tests, Docker, emulators and a browser, on a fast machine whose disk is still there tomorrow. Compare it one to one: boat vs E2B and boat vs Deno Sandbox.
Questions people ask
Is E2B cheaper than Deno Sandbox?
Deno often costs less per hour, but it fits none of the five scenarios on this page as written. For sandboxes for your users, E2B Pro+ comes to $1,395 a month against $783 a month for Deno Builder, but Builder allows only 20 at once per region, not the 300 needed.
Which is faster, E2B or Deno Sandbox?
For CPU work there is no direct comparison, because Deno Sandbox is not in the benchmark. E2B did 12.61 runs per second at 4 vCPU / 8 GB and boat did 26.69. For start time, Deno says a sandbox starts in under 200 ms, and E2B boots from a snapshot.
How long can each sandbox run?
An E2B sandbox runs up to 1 hour on Hobby and 24 hours on Pro, and pausing resets the clock. A Deno sandbox lives up to 30 minutes, and longer work can be promoted to a Deno Deploy app. boat has no session cap on paid plans.
Can E2B or Deno Sandbox run Docker?
E2B runs Docker inside the sandbox but does not support nested virtualization. Deno's docs do not say Docker works and do not mention nested virtualization. boat runs Docker and systemd and exposes /dev/kvm for Android emulators and VMs.
Do they keep files between runs?
E2B can pause a sandbox with its memory and disk and resume it in about a second. A Deno sandbox wipes its root disk when it ends, unless you mount a volume, available only in Chicago. boat saves the whole disk every minute and on stop.
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.
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