Cloudflare Sandbox vs Sprites
Both run each sandbox in its own Firecracker microVM and both sleep when idle. Cloudflare Sandbox is a container you build and drive from a Worker, and its disk starts fresh after sleep; a Sprite is a fixed 8 vCPU Linux computer from Fly.io that keeps its 100 GB disk and wakes with its processes still in memory.
The companies and products
Cloudflare Sandbox
Cloudflare Sandbox SDK runs untrusted or AI-generated code in Linux containers on Cloudflare's network, driven from a Cloudflare Worker.
Each sandbox is a Cloudflare Container backed by a Durable Object, and each container runs in its own Firecracker microVM with its own kernel and network. You build a linux/amd64 image, pick an instance type of up to 4 vCPU and 12 GiB, and reach the sandbox through your own Worker. It suits teams already on Workers who want short-lived sandboxes that sleep when idle; for code that only calls known methods, Cloudflare also offers Dynamic Workers, which run JavaScript in V8 isolates.
- Largest instance
- 4 vCPU, 12 GiB memory, 20 GB disk (defaults, can be raised)
- Account limits
- 1,500 vCPU, 6 TiB memory and 30 TB disk running at once
- Compliance
- Cloudflare holds a SOC 2 Type II report
Sprites
Sprites is Fly.io's product for agents: persistent Linux computers you create by API or CLI, which sleep when idle and wake on the next request.
Each Sprite is a Firecracker microVM with 8 vCPU, memory the platform manages, and a 100 GB ext4 disk that syncs to object storage. It runs one managed Ubuntu image with Claude Code, Codex, Gemini CLI and Cursor preinstalled, gets an HTTPS URL that wakes it, and bills only for the CPU and memory it actually uses while awake. It is built for coding agents, dev environments and user code that sit idle most of the time.
- Isolation
- Firecracker microVM per Sprite
- Regions
- Not selectable for Sprites
- Free start
- $30 trial credit per organization
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. “13th cheapest of 345” means 12 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 | Cloudflare Sandbox: price rank | Sprites: price rank | bochka: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Sprites keeps a long session's files on a 100 GB disk, while Cloudflare starts from a fresh disk after sleep; bochka keeps the disk too and adds systemd, /dev/kvm and a desktop. | 162nd of 367, with limits $1,543 a month | 66th of 367, with limits $546 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An always-on assistant needs its files and open connections to stay put: Cloudflare wipes the disk on sleep, Sprites drops connections on every pause, and bochka keeps the machine running. | 207th of 366, with limits $2,188 a month | 157th of 366, with limits $1,166 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 Cloudflare fits short code-interpreter calls best of the three: CPU is billed only while busy and a container wakes on the next request, with your own image ready to go. | 13th cheapest of 345 $144 a month | 93rd of 345, with limits $140 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 Cloudflare fits sandboxes for your users with egress rules written as Worker code; Sprites does not publish how many machines can run at once, so 300 at once is not confirmed. | 9th cheapest of 361 $731 a month | 56th of 361, with limits $428 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 | 144th of 360, with limits $9,428 a month | 105th of 360, with limits $6,540 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 | 45th cheapest of 364 $818 a month | 125th of 364, with limits $545 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 Sprites fits CI better than Cloudflare, with a 100 GB disk against 20 GB by default; bochka adds full Docker and /dev/kvm for Android and VM builds. | 301st of 377, with limits $704 a month | 63rd cheapest of 377 $476 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB A dev box should keep its files: Sprites does and wakes in under a second, Cloudflare starts fresh after sleep, and bochka adds SSH and systemd. | 70th cheapest of 368 $93 a month | 213th of 368, with limits $27 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 Cloudflare nor Sprites ships a desktop, so you would build one into your image or install it yourself; bochka streams a 60fps desktop with Chromium. | 166th of 369, with limits $460 a month | 85th of 369, with limits $136 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 | 210th of 367, with limits $233 a month | 171st of 367, with limits $122 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 | 250th of 346, with limits $286 a month | 229th of 346, with limits $206 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 | 169th of 338, with limits $5,741 a month | 141st of 338, with limits $4,113 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 Red-team runs often need raw TCP and full root networking; neither Cloudflare nor Sprites takes raw TCP from outside, while bochka does and also exposes /dev/kvm. | 239th of 360, with limits $325 a month | 210th of 360, with limits $223 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 | Cloudflare Sandbox | Sprites | bochka |
|---|---|---|---|
| Isolation | Firecracker microVM per container, own kernel and network | Firecracker microVM per Sprite, own kernel | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Machine size | Pick an instance type up to 4 vCPU / 12 GiB / 20 GB disk by default (can be raised); no 4 vCPU / 8 GB size | Fixed 8 vCPU and 100 GB disk; memory set and scaled by the platform | You choose, up to 16 vCPU / 32 GB depending on plan |
| Image | Your own linux/amd64 container image | One managed Ubuntu 25.10 image; you install on top | Full VM with root; you install what you need |
| Files between sessions | Fresh disk after sleep; snapshots (public beta, kept 30 days) or R2 backups when your code saves them | 100 GB disk kept and synced to object storage; checkpoints restore in place | Disk kept; saved every minute and on stop; a stopped sandbox costs nothing |
| Idle behavior | Stops after an inactivity timeout and wakes on the next request, from a fresh disk | Pauses about 30 seconds after activity stops; wakes in 100 to 500 ms with memory, or 1 to 2 s after a cold stop | Runs until you stop it or its time to live ends; no idle timer |
| Fork a running sandbox | No fork; restore a snapshot or backup into a new sandbox | No fork in the public API or CLI | Yes, without stopping it |
| Docker inside | docker:dind with iptables and IP forwarding turned off | Docker runs, but users report docker exec fails for containers whose main process is not root; no systemd | Full Docker, root and systemd |
| Nested virtualization | Not documented | No /dev/kvm in the docs | Yes, /dev/kvm for Android emulators and VMs |
| Desktop and browser | Built-in desktop removed in SDK 0.10.2; bring your own | Headless; no desktop or browser product | 60fps desktop and Chromium, computer-use API, embeddable stream |
| Inbound traffic | HTTP and WebSocket previews routed through your Worker; no raw TCP or public IP | One HTTPS URL to one HTTP port; other ports and SSH only through the sprite proxy CLI | HTTPS URLs for up to 50 ports, token-protected; raw TCP; SSH; own IPv4 or IPv6 |
| Egress control | allowedHosts deny-by-default list plus outbound handlers you write in Worker code | Optional DNS-based domain allowlist set from outside; private IPs always blocked | Open internet, no provider-side allowlist |
| Keeping keys out of the sandbox | Your outbound handler adds the token for any HTTP or HTTPS host; you write the code | Connectors gateway holds the token for GitHub, Slack or any HTTP API, with path allow and block lists | Managed proxy for model providers and any HTTPS API; switch a credential to another account when credits run out |
| Coding agents | Run Claude Code, Codex, OpenCode or Pi in your image; OpenCode has an SDK helper | Claude Code, Codex, Gemini CLI and Cursor preinstalled, run through exec or a console | Seven agents preinstalled, with a prompt, steer and events API to drive them from outside |
| Regions | Several regions across Cloudflare's network, nearest free instance picked | Region not selectable | EU only (Germany, Finland, France), with EU data residency |
Every feature Battleships tracks (43)
| Feature | Cloudflare Sandbox | Sprites | bochka |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Yes | Yes |
| Nested virtualization | No | No | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Not published | No | Yes |
| Desktop GUI | No | No | Yes |
| Browser | No | No | Yes |
| Computer-use API | No | No | Yes |
| SSH | Yes | No | Yes |
| Persistent disk | No | Yes | Yes |
| Pause/resume | No | Yes | Yes |
| Automatic snapshots | No | Yes | 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 | Yes | Yes | Yes |
| Idle auto-stop | Yes | Yes | No |
| Wake on request | Yes | Yes | 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 | Yes | No | Yes |
| MCP server | No | Yes | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | No | No | No |
| Self-hosting | No | No | No |
| BYOC | No | No | No |
| Open source | Yes | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | No | Not published | Yes |
| Usage per sandbox (API) | Not published | No | Yes |
| Audit logs | Yes | Not published | No |
| SSO | Yes | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | Yes | Yes | No |
| EU data residency | Yes | No | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
Neither Cloudflare Sandbox nor Sprites has a result on the hpc-sandbox-benchmarks Node.js build-and-test loop we use, so there is no comparable CPU number between them. bochka did 26.69 runs per second on that test at 4 vCPU / 8 GB, 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. Cloudflare Sandbox and Sprites 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 | Cloudflare Sandbox, a month | Sprites, a month | bochka, 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 · Workers Paid · with limits | $23 · Pay-as-you-go | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $148 · Workers Paid · with limits | $92 · Pay-as-you-go | $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 | $1,660 · Workers Paid · with limits | $1,120 · Pay-as-you-go | $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 | $476 · Workers Paid | $314 · Pay-as-you-go · 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 · Workers Paid · with limits | $1,134 · Pay-as-you-go · with limits | $2,000 · $2000/mo · with limits |
Cloudflare Sandbox: You need Workers Paid ($5 a month minimum). CPU is billed only while in use; memory and disk are billed on the instance size you picked until the container sleeps, and 4 vCPU always comes with 12 GiB. Durable Object and Worker requests are billed on top.
Sprites: Sprites bills CPU time at $0.0385 per CPU-hour and actual memory at $0.021875 per GB-hour, only while the Sprite is awake, plus storage on the bytes you write. Optional plans buy fixed CPU-hour, memory-hour and storage allowances, not credit.
Sprites: Plans start at $20 a month, and the whole fee is usage credit, billed per second while a sandbox runs. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Cloudflare's disk resets after sleep, so the three agent scenarios that keep 50 GB of files between days do not fit without your own snapshot or backup code, and an account runs 1,500 vCPU at once by default, short of the 2,000 the 1,000-job burst needs. Sprites does not publish how many Sprites can run at once on pay as you go, so 300 sandboxes for your users and 1,000 jobs at once are not confirmed, and creation is 10 a minute without a plan. On bochka that burst runs into start limits: the $2,000 plan allows 600 starts an hour and queues bursts above 90 a minute.
| Scenario | Cloudflare Sandbox | Sprites | bochka |
|---|---|---|---|
| One coding agent, workdays |
| None that bite | None that bite |
| One agent that never stops |
| None that bite | None that bite |
| 50 agents in parallel |
|
| None that bite |
| Sandboxes for your users | None that bite |
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Cloudflare Sandbox when
your app already runs on Workers, you want your own container image, and your sandboxes are short sessions that can start from a fresh disk.
- Your own image and size. Teams that need a custom toolchain can ship their own container image and pick a smaller or larger instance type per container class.
- Egress rules you can program. Cloudflare can block every host except the ones you list, and run your own Worker code on each outbound request.
- Next to the rest of Workers. If your app already runs on Workers, sandboxes sit next to Durable Objects and R2, in several regions of Cloudflare's network.
Use Sprites when
your agents or apps sit idle most of the day, should keep their files, and should wake on a request in under a second.
- A disk that stays. Each Sprite keeps a 100 GB disk across sleeps, so an agent finds its repo and packages where it left them.
- Wakes fast with memory intact. A Sprite pauses when idle and wakes in 100 to 500 ms with its processes still in memory, billing only real CPU and memory use.
- Agents and platforms ready. Claude Code, Codex, Gemini CLI and Cursor come preinstalled, and Sprites can back Claude Managed Agents and Cursor Cloud Agents.
Where bochka fits
Both Cloudflare Sandbox and Sprites are built around machines that sleep when nobody is using them. If your agents work for hours on builds, tests, Docker, emulators or a browser, bochka gives each one a full VM that keeps running, keeps its disk and can be driven from outside.
Files that stay, and forks
On Cloudflare an agent loses its repo and packages on sleep unless your code saves a snapshot that expires after 30 days. Sprites keeps the disk, but neither can fork a running sandbox to try two fixes from one state.
A fuller machine
Cloudflare tops out at 4 vCPU and 20 GB of disk by default with iptables off; Sprites is a fixed 8 vCPU box with no systemd. Neither documents /dev/kvm or ships a desktop, so emulators and computer use need workarounds.
Reach it and drive it from outside
Cloudflare routes traffic through your Worker with no raw TCP, and Sprites has one public HTTP port with SSH through its proxy CLI. bochka gives 50 HTTPS ports, raw TCP, SSH and an API to prompt and steer agents inside.
Use bochka when your agents need a full machine for hours: systemd, full Docker, emulators, many ports, a desktop and browser, forks, and an API to drive the agents inside from outside. Compare it one to one: bochka vs Cloudflare Sandbox and bochka vs Sprites.
Questions people ask
Is Cloudflare Sandbox cheaper than Sprites?
In all five scenarios we priced, Sprites comes out lower: one agent that never stops is $92 a month on Sprites against $148 on Cloudflare, and 50 agents in parallel are $1,120 against $1,660. Cloudflare's agent estimates also lack a disk that stays, so they do not fit. bochka comes to $26 and $317 for those two.
Which is faster, Cloudflare Sandbox or Sprites?
Neither has a result on the CPU benchmark we use, so we cannot compare them. A Sprite always has 8 vCPU, while Cloudflare's largest default instance has 4. bochka did 26.69 runs per second at 4 vCPU / 8 GB.
Do they keep my files?
Sprites does: each Sprite keeps a 100 GB disk across sleeps. Cloudflare starts from a fresh disk after sleep unless your code saved a snapshot (public beta, kept 30 days) or a backup to R2. bochka keeps the disk and saves it every minute.
Can Cloudflare Sandbox or Sprites run Docker?
Both can, with limits. Cloudflare supports docker:dind with iptables and IP forwarding turned off, and on Sprites users report docker exec fails for containers whose main process is not root. bochka runs full Docker with systemd.
Can I SSH into them?
Not directly on Sprites: you install an SSH server and tunnel it through the sprite proxy CLI. Cloudflare reaches containers through your Worker, with no raw TCP or public IP. bochka sandboxes have SSH, raw TCP and a dedicated IP.
Where do they run?
Cloudflare places containers in several regions of its network and picks the nearest free one. Sprites does not let you choose a region. bochka runs only in the EU, in Germany, Finland and France.
Try bochka
Install the CLI, then run bochka new.
Product preview
More comparisons
- bochka vs Cloudflare Sandbox
- bochka vs Sprites
- E2B vs Cloudflare Sandbox
- Daytona vs Cloudflare Sandbox
- Modal vs Cloudflare Sandbox
- Vercel Sandbox vs Cloudflare Sandbox
- Cloudflare Sandbox vs Blaxel
- Cloudflare Sandbox vs Runloop
- Cloudflare Sandbox vs Tensorlake
- Cloudflare Sandbox vs Morph Cloud
- Cloudflare Sandbox vs CodeSandbox SDK
- Cloudflare Sandbox vs Northflank