Vercel Sandbox
Firecracker microVM sandboxes on Vercel’s infrastructure, persistent by default and billed on active CPU, with fine-grained egress control. A polished microVM sandbox with standout egress and billing design; the obvious pick for Vercel-centric teams.
Overview
Vercel Sandbox runs code in Firecracker microVMs on Vercel’s infrastructure and has been generally available since January 2026. Sandboxes are persistent by default: the filesystem is snapshotted on stop and restored on resume, so a coding agent can pick up where it left off.
Two features stand out for agent security and cost: a firewall with credential brokering that injects secrets at the network layer so they never enter the sandbox, and active-CPU billing that charges CPU only while code is actually running — useful when agents spend most of their time waiting on a model.
Notable
- Generally available since January 30, 2026.
- Used in production by v0, Blackbox AI and RooCode per Vercel’s GA announcement.
Vercel Sandbox specifications
| Attribute | Details |
|---|---|
| Isolation | Firecracker microVM with a dedicated kernel per sandbox |
| Deployment | Hosted platform |
| Open source | No (SDK and CLI Apache-2.0) |
| SDKs and interfaces | JavaScript/TypeScript, Python |
| Cold start (vendor claim) | “Start in milliseconds” (vendor claim, no figure); snapshot resume faster than fresh start |
| Max session length | 5 min default; up to 45 min per session on Hobby and 24 hours on Pro/Enterprise; persistent sandboxes can be resumed indefinitely |
| Persistence | Persistent by default — filesystem auto-snapshotted on stop and restored on resume; manual snapshots; Drives (beta) and S3 mounts |
| GPU | Not documented |
| Networking | Firewall modes allow-all, deny-all or domain/CIDR rules, updatable at runtime; credential brokering injects headers so secrets never enter the sandbox; public URLs for up to 15 ports |
| Pricing | Active CPU $0.128/hour (billed only while CPU is used) + provisioned memory $0.0212/GB-hour + $0.60 per million creations, plus storage and transfer (iad1 rates) |
| Free tier | Hobby: 5 active-CPU hours, 420 GB-hours memory and 5,000 creations per month |
| Compliance | Runs on Vercel infrastructure with SOC 2 Type II (company-wide) |
| Regions | 19 regions, selectable per sandbox |
Facts from Vercel Sandbox’s public documentation, verified November 8, 2026. Performance numbers are vendor claims.
Strengths and trade-offs
Strengths
- You deploy on Vercel or use the AI SDK
- You want secrets brokered outside the sandbox
- Your agents idle while waiting on models and you want active-CPU billing
- You want persistent-by-default microVMs
Trade-offs
- No GPU support documented
- Hosted only — no self-hosting or BYOC
- Hobby sessions capped at 45 minutes
Best for: Teams on Vercel and agent builders who want microVM isolation, active-CPU billing and credential brokering.
Where Vercel Sandbox ranks
How Vercel Sandbox compares
| Sandbox | Isolation | Open source | Self-host / BYOC | Cold start (vendor) | Max session | Snapshots / pause | GPU | SDKs |
|---|---|---|---|---|---|---|---|---|
| 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 |
| Cloudflare Sandbox SDK | MicroVM (Containers) | Yes | No / No | 1–3 s | No fixed cap | Yes / Not documented | Not documented | TypeScript (Workers) |
| Daytona | Containers or VMs | No | Not documented / Yes | <90 ms | Unlimited | Yes / Yes | Yes | Python, TypeScript, Ruby, Go, Java |
| 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 |
| Together Code Sandbox | MicroVM | No | No / Not documented | 0.5 s (snapshot) | Until terminated | Yes / Yes | Not documented | Python, TypeScript |
Head-to-head: E2B vs Vercel Sandbox · Daytona vs Vercel Sandbox · Modal Sandboxes vs Vercel Sandbox · Vercel Sandbox vs Cloudflare Sandbox SDK · Vercel Sandbox vs Fly.io Sprites
Frequently asked questions
What is Vercel Sandbox?
How does Vercel Sandbox isolate code?
Is Vercel Sandbox open source?
How much does Vercel Sandbox cost?
What are the best Vercel Sandbox alternatives?
Sources
Cite this page
Agent Sandboxes. (2026). Vercel Sandbox. agentsandboxes.org. Last reviewed November 8, 2026. https://agentsandboxes.org/sandboxes/vercel-sandbox/
Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.