CreateOS Sandbox vs Cloudflare Sandbox
Pick Cloudflare Sandbox if you build on Workers and Durable Objects and want sandboxes closed to the internet by default, with credentials kept in the Worker. Pick CreateOS Sandbox if you want to create and drive sandboxes directly over REST or SDKs in six languages without writing a Worker, need up to 8 vCPU per sandbox, or want a pause that keeps memory.
Pricing at a glance
CreateOS rates verified 17 October 2026. Cloudflare Sandbox pricing as published on 17 October 2026. Rates billed per GB rather than per GiB, or as bundled sizes, are quoted as published rather than converted.
CreateOS Sandbox
- Compute
- $0.0362 /vCPU-hr
- Memory
- $0.0116 /GiB-hr
- No egress fees, 50 GiB bandwidth budget
- vCPU stops billing while paused
Cloudflare Sandbox
- Compute
- See below
- Memory
- $0.0090 /GiB-hr
Cloudflare Sandbox needs the Workers Paid plan ($5 per month) and bills memory at $0.0000025 per GiB-second, CPU at $0.000020 per active vCPU-second and disk at $0.00000007 per GB-second beyond monthly allowances, with egress from $0.025 per GB, as of 17 October 2026.
Where CreateOS Sandbox fits better
What CreateOS Sandbox brings to this matchup, with a plain note on where Cloudflare Sandbox has the edge.
- No Worker or Durable Object required: create sandboxes from REST, the CLI, MCP or SDKs in six languages.
- Pause saves memory and CPU state as well as disk; Cloudflare's snapshots are filesystem-only and in beta.
- No inactivity cut-off; Cloudflare instances stop after an inactivity timeout of at most 6 hours.
- Larger shapes: up to 8 vCPU / 16 GB on Enterprise, against Cloudflare's default ceiling of 4 vCPU / 12 GiB.
Where Cloudflare Sandbox is strong
Cloudflare Sandbox is deny-by-default for Containers, and your Worker holds the credentials, so sandboxed code can call authenticated APIs without ever seeing the token. It runs on Cloudflare's global network with cheap provisioned memory and CPU billed only when active.
Which to pick
Pick CreateOS Sandbox if
- You want to call a sandbox API from Python, Go, Rust, C# or Java with no Worker in between.
- An agent session needs to pause with its processes and resume hours later.
- You need more than 4 vCPU in one sandbox.
Pick Cloudflare Sandbox if
- Your stack already runs on Cloudflare Workers and Durable Objects.
- You want internet off in every sandbox unless your Worker allows the request.
- You need large account-wide pools: 1,500 concurrent vCPU by default.
Head-to-head comparison
Every dimension side by side, checked on 17 October 2026 against each vendor's own docs and pricing pages. "Not published" means we could not find it on the vendor's pages, not that the feature is missing.
| Dimension | CreateOS Sandbox | Cloudflare Sandbox |
|---|---|---|
| Isolation | Firecracker micro-VM with its own guest kernel | Firecracker micro-VM per container instance; V8 isolate for JavaScript-only Dynamic Workers |
| Pause and resume | Saves disk, memory and CPU state; vCPU billing stops, memory and storage still bill | Runs while active and stops after an inactivity timeout; filesystem snapshots in beta, kept 30 days; no memory snapshot published |
| Fork | Forks a paused sandbox into many independent copies | Not published as a fork; a saved filesystem snapshot can start a new instance |
| Outbound network default | Open with no rules; deny-by-default once any host, IP, CIDR or wildcard rule exists, enforced on the host outside the VM | Closed for Containers; only requests your Worker's outbound handler intercepts leave |
| Inbound access | Closed by default; opt-in HTTPS URL | No public port by default; the Worker forwards requests |
| Largest size | 8 vCPU / 16 GB on Enterprise; 8 vCPU / 8 GB on Pro | 4 vCPU / 12 GiB / 20 GB by default, raisable on request |
| Concurrency | 1 / 5 / 20 / 30 by plan (Free to Enterprise); paused sandboxes count | Account limits of 1,500 vCPU and 6 TiB memory by default, raisable |
| Session length | No cap; optional idle auto-pause from 60 s to 24 h, off by default | Inactivity timeout configurable up to 6 hours |
| Billing | Per second: $0.03616363/vCPU-hr, $0.01159025/GiB-hr, $0.0001584/GB-hr storage; no egress fees, 50 GiB bandwidth budget per sandbox | Workers Paid $5/month; memory $0.0000025 per GiB-second; CPU $0.000020 per active vCPU-second; egress from $0.025/GB |
| SDKs and interfaces | TypeScript, Go, Python, Rust, C#, Java (all but TypeScript pre-1.0), CLI, MCP, REST | @cloudflare/sandbox TypeScript SDK used from a Worker; Wrangler CLI |
Common questions
Do I need a Cloudflare Worker to use Cloudflare Sandbox?
Yes. Cloudflare Sandbox is controlled from a Worker and a Durable Object, which also route requests and hold credentials. CreateOS Sandbox is called directly through REST, the CLI, an MCP server or SDKs in TypeScript, Go, Python, Rust, C# and Java.
Is outbound internet blocked by default in Cloudflare Sandbox?
For Containers, yes: enableInternet is false by default, and only requests your Worker's outbound handler intercepts leave. CreateOS Sandbox starts open, then switches to deny-by-default as soon as you add any host, IP, CIDR or wildcard rule, enforced on the host outside the VM.
How long does a Cloudflare Sandbox instance stay running?
It runs while its main process lives and requests arrive, with an inactivity timeout you can set up to 6 hours. A CreateOS sandbox has no session cap and runs until you pause or destroy it; idle auto-pause is optional and off by default.
Which is cheaper for memory, Cloudflare Sandbox or CreateOS?
Cloudflare, on list price: $0.0000025 per GiB-second, about $0.009 per GiB-hour, after 25 GiB-hours a month included. CreateOS charges $0.01159025 per GiB-hour. Cloudflare also bills CPU only on active use, plus the $5 Workers Paid plan and egress from $0.025 per GB beyond the included amount.
Sources
Checked 17 October 2026.
See CreateOS Sandbox for yourself
Book a demo, or explore the Sandbox and its pricing.