CreateOS Sandbox vs Modal
Pick Modal if your sandboxes need GPUs or sit next to inference and training jobs you already run on Modal. Pick CreateOS Sandbox if your agent sessions must pause with memory and resume later, run past 24 hours, or need SDKs beyond Python at a lower published vCPU rate.
Pricing at a glance
CreateOS rates verified 17 October 2026. Modal 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
Lower compute rate- Compute
- $0.0362 /vCPU-hr
- Memory
- $0.0116 /GiB-hr
- No egress fees, 50 GiB bandwidth budget
- vCPU stops billing while paused
Modal
- Compute
- $0.0710 /vCPU-hr
- Memory
- $0.0240 /GiB-hr
Modal bills sandboxes per second at $0.00003942 per physical core-second (one core is 2 vCPU) and $0.00000667 per GiB-second, with egress at $0.04 per GiB beyond the included allowance and plans at $0, $250 per month or custom, as of 17 October 2026.
Where CreateOS Sandbox fits better
What CreateOS Sandbox brings to this matchup, with a plain note on where Modal has the edge.
- Pause and resume keep disk, memory and CPU state in the same sandbox. Modal sandboxes have no pause; state carries over through snapshots into a new sandbox.
- No session cap. Modal sandboxes default to a 5-minute lifetime and top out at 24 hours.
- Every sandbox is a Firecracker micro-VM with its own kernel; Modal defaults to gVisor and offers a VM runtime as an option.
- Lower published rates: $0.03616363 per vCPU-hour and $0.01159025 per GiB-hour, against Modal's sandbox rates of about $0.071 and $0.024.
Where Modal is strong
Modal puts sandboxes inside a full serverless GPU platform. One account can run untrusted code, attach a GPU from a T4 up to a B300, and call inference functions you have deployed, all billed per second.
Which to pick
Pick CreateOS Sandbox if
- An agent must pause mid-task and resume with its processes intact.
- Sessions run longer than 24 hours.
- Your backend is in TypeScript, Go, Rust, C# or Java; Modal's JavaScript and Go SDKs are beta.
Pick Modal if
- Your sandboxed code needs a GPU.
- You already run inference or training on Modal and want one bill.
- You want up to 5,000 containers on the Team plan.
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 | Modal |
|---|---|---|
| Isolation | Firecracker micro-VM with its own guest kernel | gVisor by default and required for GPU; optional VM runtime with its own Linux kernel |
| Pause and resume | Saves disk, memory and CPU state; vCPU billing stops, memory and storage still bill | No pause; filesystem and directory snapshots (30-day default TTL); memory snapshots are an early release that expires after 7 days |
| Fork | Forks a paused sandbox into many independent copies | No named fork; new sandboxes start from a filesystem or memory snapshot |
| 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 | Open; block_network, CIDR allowlist, or domain allowlist (beta, TLS on port 443 only) |
| Largest size | 8 vCPU / 16 GB on Enterprise; 8 vCPU / 8 GB on Pro | CPU and memory maximum not published; disk up to 3.0 TiB |
| Concurrency | 1 / 5 / 20 / 30 by plan (Free to Enterprise); paused sandboxes count | Starter 100 containers + 10 GPU; Team 5,000 + 50 GPU; Enterprise custom |
| Session length | No cap; optional idle auto-pause from 60 s to 24 h, off by default | 5-minute default, configurable up to 24 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 | Per second: about $0.071 per vCPU-hour and $0.024 per GiB-hour; egress $0.04/GiB beyond included |
| SDKs and interfaces | TypeScript, Go, Python, Rust, C#, Java (all but TypeScript pre-1.0), CLI, MCP, REST | Python SDK; JavaScript and Go SDKs in beta; CLI |
| GPU | No GPU | Yes: T4 through B300, on the gVisor runtime only |
Common questions
Can a Modal sandbox be paused and resumed?
No. Modal sandboxes terminate, and you keep state with filesystem, directory or memory snapshots that start a new sandbox. Memory snapshots are an early-release feature that expires after 7 days. CreateOS Sandbox pauses in place, saving disk, memory and CPU state, and resumes the same sandbox.
How long can a Modal sandbox run compared with a CreateOS sandbox?
A Modal sandbox defaults to 5 minutes and can be set up to 24 hours; for longer work Modal suggests snapshotting and restoring into a new sandbox. A CreateOS sandbox has no lifetime cap and runs until you pause or destroy it, with optional idle auto-pause from 60 seconds to 24 hours.
Is Modal or CreateOS Sandbox better for GPU code execution?
Modal, because it offers GPUs from T4 through A100, H100, H200, B200 and B300 in sandboxes on its gVisor runtime. CreateOS Sandbox has no GPU shapes. If your sandboxed code is CPU-bound agent work, CreateOS charges a lower published vCPU and memory rate.
What isolation does Modal use for sandboxes?
Modal uses gVisor by default, and gVisor is required for GPU sandboxes. A VM runtime with its own Linux kernel is available for workloads such as Docker, FUSE or nested cgroups. CreateOS Sandbox runs every sandbox as a Firecracker micro-VM with its own guest kernel.
Sources
Checked 17 October 2026.
See CreateOS Sandbox for yourself
Book a demo, or explore the Sandbox and its pricing.