Sandbox guide

Provider · checked 2026-10-28

Vercel Sandbox

Firecracker microVMs inside Vercel, billed on active CPU and provisioned memory.

vercel.com/docs/sandbox12 providersSources linked

Vercel Sandbox runs untrusted or agent-generated code in Firecracker microVMs, managed through a CLI, JavaScript SDK or Python SDK.

It is part of the Vercel platform rather than a separate product: usage sits on the Vercel plan, and the Hobby plan is restricted to non-commercial use.

At a glance

Who it is forTeams already on Vercel who want agent code execution with many regions and familiar account controls.
IsolationFirecracker microVM with a dedicated kernel. Root access, Docker and FUSE are documented; systemd and nested virtualisation are not.
Sizes1 or even numbers of vCPUs from 2 to 32 depending on plan, 2 GB of memory per vCPU, and 64 GB of ephemeral NVMe. Hobby caps at 4 vCPU / 8 GB, Pro at 8 / 16, Enterprise at 32 / 64. Nineteen regions; no GPU published.

How it bills

ModelMetered usage against the Vercel plan, with a monthly credit on Pro.
MeterActive CPU at $0.128 per CPU-hour, excluding time waiting on I/O; provisioned memory at $0.0212 per GB-hour with a one-minute minimum; creations, data transfer, snapshots and drives separately.
While stoppedNo CPU or memory charge, but snapshots and drives keep billing. Persistent sandboxes create a billable snapshot when they stop.
Plan feeVercel Pro is $20 a month and includes $20 of usage credit, which expires monthly.
MinimumMemory bills in one-minute increments. Hobby has included quotas and pauses creation when they are exhausted.

How Vercel Sandbox lets you try before paying is on Trials and free tiers.

Where it stands out

  • Firecracker isolation with root and Docker inside.
  • Nineteen regions.
  • Credential brokering keeps secrets out of the guest.
  • Drives are billed on used data, not provisioned size.
  • Snapshots expire after 30 days by default and can be kept indefinitely.

Using it without writing code

DashboardThe Vercel dashboard can stop or delete a sandbox and shows a lifecycle activity log.
Without codeNo documented no-code path; the workflows are CLI and SDK.
SignupA Vercel account. Card requirement depends on the plan and trial path; Hobby is non-commercial only.
Docs and supportVercel's docs cover sandbox concepts, SDK, pricing and limits. Support follows the Vercel plan.

Caveats and contradictions

Shown as the research found them. A contradiction means the provider's own pages disagree; an open question means the answer is not published.

  1. 01

    Persistence is billed by default Open question

    Persistent sandboxes save their filesystem when stopped, and each automatic snapshot consumes snapshot storage billed separately from compute.

  2. 02

    The session limit is not a lifetime limit Open question

    The maximum duration applies to a single session: 45 minutes on Hobby, 24 hours on Pro and Enterprise. Persistent sandboxes can be resumed into a new session.

  3. 03

    Hobby is non-commercial Open question

    The Hobby plan restricts users to non-commercial, personal use only.

  4. 04

    Hobby quota reset wording differs Contradiction

    One page says creation pauses until 30 days after first use; another says until the next billing cycle.

  5. 05

    Fork is not a live memory copy Open question

    Fork uses the current saved snapshot or falls back to a fresh create from the image; manual snapshotting stops the source.

Sources

The three shared workloads

List-price illustrations, not quotes

A · 1,000 short tasks

$18.40 before credit

2 vCPU / 4 GB, 10% average CPU, deleted after each task

  • Memory4 × 166.67 h × $0.0212$14.13
  • Active CPU at 10%2 × 166.67 h × 0.10 × $0.128$4.27
  • An otherwise unused $20 Pro credit covers this, but the $20 platform fee remains.
  • Opt out of persistence, or deleting a sandbox leaves billable snapshots.

B · One always-on box

$161.18 before credit, and not a continuous session

4 vCPU / 8 GB, 10% average CPU, 730 running-equivalent hours

  • Memory8 × 730 × $0.0212$123.81
  • Active CPU at 10%4 × 730 × 0.10 × $0.128$37.38
  • A single session cannot exceed 24 hours on Pro, so 730 hours needs restarts and snapshots.
  • 50 GiB is not a configurable disk: the standard filesystem is 64 GB, and drives are billed on used data.

The always-on workload breaks the 24-hour per-session limit, so this is a running-equivalent estimate rather than a feasible single sandbox.

C · Three hours a day

$9.94 before credit

2 vCPU / 4 GB, 10% average CPU, 90 running hours, stopped otherwise

  • Memory4 × 90 × $0.0212$7.63
  • Active CPU at 10%2 × 90 × 0.10 × $0.128$2.30
  • A 20 GB drive holding 20 GB of data for the month adds about $1.00 plus reads and writes.
  • Retaining the filesystem as snapshots adds storage; 30 stops can create 30 snapshots.