Best Cloudflare Sandbox SDK alternatives
The strongest Cloudflare Sandbox SDK alternatives are Vercel Sandbox, E2B, Fly.io Sprites. Pick based on what you need that Cloudflare Sandbox SDK does not offer — see the reasons under each entry.
Why teams look beyond Cloudflare Sandbox SDK
A strong, programmable option for Workers developers; less suited to Python-first agent stacks.
- TypeScript/Workers only — no Python SDK
- 1–3 second cold starts are slower than microVM specialists
- Cloudflare-only; no self-hosting
Cloudflare Sandbox SDK alternatives, ranked
Vercel Sandbox
Firecracker microVM sandboxes on Vercel’s infrastructure, persistent by default and billed on active CPU, with fine-grained egress control.
- Firecracker microVM
- Pause/resume
Why it’s here: Teams on Vercel and agent builders who want microVM isolation, active-CPU billing and credential brokering. A polished microVM sandbox with standout egress and billing design; the obvious pick for Vercel-centric teams.
E2B
Open-source cloud sandboxes for AI agents, each a Firecracker microVM, with pause/resume, snapshots and forking.
- Firecracker microVM
- Open source
- Self-hostable
- BYOC
- Pause/resume
Why it’s here: Code interpreters and short-to-medium-lived agent tasks that need microVM isolation, with an open-source self-host path. The safe default for most agent builders: mature, open source, microVM-isolated and widely supported.
Fly.io Sprites
Persistent, hardware-isolated Linux computers for AI agents with a durable 100 GB disk, checkpoints, and no compute charges while idle.
- MicroVM
- Pause/resume
Why it’s here: Long-running, stateful agent computers that should cost nothing while idle. The most natural “persistent computer per agent” model, with idle-free billing.
Freestyle
Full Linux VMs for AI agents with live forking of running VMs, memory-preserving hibernation, VPCs and nested virtualization.
- VM
- Pause/resume
Why it’s here: Long-running coding agents that need full VMs — Docker, nested virtualization — with fork and hibernate. The most capable “real VM” for agents, with live forking; a strong pick for complex coding agents.
Daytona
Stateful sandboxes for AI-generated code — Linux containers, Linux and Windows VMs, macOS and GPU sandboxes — with snapshots, volumes and preview URLs.
- Containers or VMs
- BYOC
- GPU
- Pause/resume
Why it’s here: Long-lived, stateful agent workspaces that need many SDK languages, GPUs, or Windows and macOS sandboxes. The strongest choice for stateful coding-agent workspaces and breadth of sandbox types; note the shift away from open source.
Cloudflare Sandbox SDK vs alternatives
| Sandbox | Isolation | Open source | Self-host / BYOC | Cold start (vendor) | Max session | Snapshots / pause | GPU | SDKs |
|---|---|---|---|---|---|---|---|---|
| Cloudflare Sandbox SDK | MicroVM (Containers) | Yes | No / No | 1–3 s | No fixed cap | Yes / Not documented | Not documented | TypeScript (Workers) |
| Vercel Sandbox | Firecracker microVM | No | No / No | Milliseconds (claim) | 24 h (Pro) | Yes / Yes | Not documented | JavaScript/TypeScript, Python |
| E2B | Firecracker microVM | Yes | Yes / Yes | Not documented | 1 h / 24 h (Pro) | Yes / Yes | No | Python, JavaScript/TypeScript |
| Fly.io Sprites | MicroVM | No | No / No | 0.1–2 s wake | Unlimited | Yes / Yes | No | JavaScript/TypeScript, Go, Python, Elixir |
| Freestyle | VM | No | No / Not documented | 65 ms | Unlimited (paid) | Yes / Yes | Not documented | TypeScript |
| Daytona | Containers or VMs | No | Not documented / Yes | <90 ms | Unlimited | Yes / Yes | Yes | Python, TypeScript, Ruby, Go, Java |
Frequently asked questions
What is the best alternative to Cloudflare Sandbox SDK?
Is there an open-source alternative to Cloudflare Sandbox SDK?
Cite this page
Agent Sandboxes. (2026). Best Cloudflare Sandbox SDK alternatives. agentsandboxes.org. Last reviewed November 8, 2026. https://agentsandboxes.org/alternatives/cloudflare-sandbox/
Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.