Vercel Sandbox vs Railway Sandboxes

Vercel Sandbox and Railway Sandboxes provide isolated environments for running untrusted and AI-generated code. They differ in isolation, reusable environments, networking, runtime limits, pricing, and infrastructure integration.

• Vercel Sandbox uses Firecracker microVMs with dedicated kernels, supports Node.js, Python, and OCI images, and offers usage-based pricing across Hobby, Pro, and Enterprise plans.
• Railway Sandboxes run on Railway's virtual machine primitive and combine templates, checkpoints, forks, private networking, and six preinstalled coding agents.
• Railway Sandboxes remain in Priority Boarding as of July 2026. Vercel Sandbox is generally available but runs only in the iad1 region.
• Vercel Sandbox sessions can run for up to 24 hours on Pro and Enterprise. Railway uses idle timeouts of up to 120 minutes on Hobby and Pro.
• Northflank adds GPU sandboxes, persistent and ephemeral modes, no session-duration limit, multi-region managed cloud, and self-serve BYOC for teams taking agent workloads into production.

Vercel Sandbox is an ephemeral compute service for running untrusted or user-generated code, including AI-agent output, code generation, isolated tests, and temporary development servers.

Each sandbox runs in a Firecracker microVM with its own filesystem, network, and dedicated kernel. SDK and CLI interfaces cover creation, commands, files, and lifecycle operations.

The built-in images include Node.js 22, 24, and 26, plus Python 3.13, with Node.js 24 as the default. Teams can also import an OCI image when they need a custom environment. Snapshots preserve files and installed packages for reuse across later runs.

Vercel Sandbox is available on Hobby, Pro, and Enterprise plans. Its runtime, concurrency, and resource limits vary by plan, and sandboxes currently run in the iad1 region.

Railway Sandboxes are short-lived Linux environments created through the Railway dashboard, CLI, or TypeScript SDK. Each sandbox is scoped to a Railway environment and runs on Railway's virtual machine primitive.

Templates create a repeatable base, checkpoints capture prepared disk state, and forks copy a running sandbox's filesystem without its active processes. Commands can continue after a client disconnects and be reattached later.

The default image includes git, Node.js, npm, mise, and six coding agents: Claude Code, OpenAI Codex, Cursor, Droid, OpenCode, and Pi. Agent credentials and configuration still need to be passed into the environment when required.

As of July 2026, Railway Sandboxes are available through Priority Boarding, Railway's opt-in beta program.

This comparison reflects product availability and pricing as of July 2026.

Vercel Sandbox runs each environment in a Firecracker microVM with a dedicated kernel. Built-in Node.js and Python images cover common agent and code-execution workloads, while OCI-image support allows teams to bring a custom environment.

Railway Sandboxes run on Railway's virtual machine primitive. Each sandbox belongs to a Railway environment, which lets the execution environment sit alongside the services and data it needs to test.

For managed or customer-controlled infrastructure, Northflank sandboxes use microVM-backed containers with separate kernel instances on Northflank Cloud or BYOC clusters.

Vercel Sandbox provides SDK and CLI operations for creating environments, running commands, editing files, and taking snapshots. Commands can run in blocking or detached mode, and later sandboxes can start from a prepared snapshot.

Railway Sandboxes place more emphasis on branching a configured workspace. Teams can create a template, prepare a sandbox, checkpoint the disk, and fork that state across parallel agent tasks. Six coding agents come preinstalled: Claude Code, OpenAI Codex, Cursor, Droid, OpenCode, and Pi.

When agents also need APIs, databases, jobs, GPUs, or previews, Northflank keeps those workloads in one control plane. Northflank Skills lets coding agents operate services, sandboxes, GPU workloads, secrets, and BYOC/BYOK infrastructure.

Railway Sandboxes can join the private network of their Railway environment and reach resources such as Postgres, Redis, internal services, and project variables. This makes them useful for testing agent-generated code against infrastructure already running on Railway.

Vercel Sandbox gives each microVM its own network. Teams can expose services through sandbox URLs and configure network access for the environment.

For workloads that need private placement, data residency, or access to existing internal systems, Northflank can run sandboxes on its managed cloud, in the team's own cloud account, or through customer VPC deployments.

Vercel Sandbox meters several resources. On Pro, active CPU costs $0.128 per hour, provisioned memory costs $0.0212 per GB-hour, creations cost $0.60 per million, data transfer costs $0.15 per GB, and snapshot storage costs $0.08 per GB-month. Active CPU excludes time spent waiting for network calls, databases, or model responses, while provisioned memory accrues for the sandbox's running time.

The Vercel Sandbox runtime timeout defaults to five minutes. Hobby sessions can run for up to 45 minutes, while Pro and Enterprise sessions can run for up to 24 hours. Concurrency ranges from 10 on Hobby to 2,000 on Pro and 2,000 or more on Enterprise. Resource ceilings range from 4 vCPUs and 8 GB of memory on Hobby to 32 vCPUs and 64 GB on Enterprise. Every sandbox receives 32 GB of ephemeral NVMe storage and runs in the iad1 region.

Railway Sandboxes bill CPU and memory while the sandbox is running, including while idle, plus network egress. Memory is approximately $50 per GB-month, vCPU is approximately $50 per vCPU-month, and egress costs $0.05 per GB. Destroying unused sandboxes or using shorter idle timeouts reduces running resource costs.

Northflank compute starts at $0.01667 per vCPU-hour and $0.00833 per GB-hour. GPU prices start at $0.80 per hour for an NVIDIA L4 24 GB, egress costs $0.06 per GB, ingress is free, and disk costs $0.15 per GB-month. For a broader model across different billing approaches, see the AI sandbox pricing comparison and full pricing details.

Vercel Sandbox snapshots preserve the filesystem, including packages and files. Railway Sandboxes offer templates for repeatable setup, checkpoints for a captured disk state, and forks for branching work from an active sandbox.

If the workload needs state to survive restarts or periods without compute, Northflank sandboxes can attach persistent volumes while keeping stateless workloads ephemeral. Teams can scale a sandbox to zero to pause compute billing while storage remains intact, then resume it with the same volume data. Databases and S3-compatible object storage can run alongside the sandbox for agent memory, artifacts, and shared state. See Sandboxes on Northflank for more detail.

Vercel Sandbox and Railway Sandboxes do not support GPU sandboxes. Vercel has announced AWS-only BYOC in Private Beta for its broader apps and agents platform. Railway does not offer self-serve BYOC.

Choose Vercel Sandbox when you want Firecracker isolation, built-in Node.js or Python environments, custom OCI images, snapshots, explicit resource ceilings, and active-CPU pricing. Check that the iad1 region and plan-specific session limits fit the workload.

Choose Railway Sandboxes when your agents need to work alongside Railway services and benefit from private networking, six preinstalled coding agents, detachable commands, templates, checkpoints, and forks. Account for the Priority Boarding beta status, running-resource billing, and idle timeout model.

Northflank is built for teams moving beyond isolated code execution into production agent infrastructure. Sandboxes can be ephemeral or persistent, run for seconds or weeks without a platform-imposed session limit, use CPU or GPU resources, and deploy on Northflank Cloud or through self-serve BYOC.

Performance has been tested at both startup and fleet scale. ComputeSDK measured 97ms median time-to-interactive sequentially and 167ms under concurrent burst load, with P99 at 216ms, in July 2026. In a separate Scale Invitational test, Northflank reached 100,000 concurrent live sandboxes from cold start in 24 seconds with zero failures.

The surrounding production stack includes databases, jobs, APIs, volumes, object storage, secrets, observability, CI/CD, previews, GPUs, and customer VPC deployments. Enterprise controls include SSO, RBAC, audit logs, network policies, and SOC 2 Type 2 certified infrastructure.

This model is already used for secure runtime workloads. Cedana uses Northflank to deploy customer environments, test secure runtimes, and operate microVM-backed workloads on Kubernetes.

As of July 2026, Railway Sandboxes are available through Priority Boarding, Railway's opt-in beta program.

Vercel Sandbox uses a Firecracker microVM with a dedicated kernel. Railway Sandboxes run on Railway's virtual machine primitive and are scoped to a Railway environment.

Vercel Sandbox charges for active CPU, provisioned memory, creations, transfer, and snapshot storage. Railway Sandboxes charge for CPU and memory while running, including while idle, plus egress.

No. Northflank supports GPU sandboxes on managed infrastructure and through self-serve BYOC.

Vercel's broader platform has AWS BYOC in Private Beta. Railway does not offer self-serve BYOC. Northflank supports self-serve BYOC across several clouds, on-premises, and bare-metal infrastructure.

• GPU sandboxes: isolation models and platform support: Compare GPU availability, isolation, and deployment options across sandbox platforms.
• AI sandbox pricing comparison: Model how CPU, memory, storage, idle time, and BYOC affect sandbox costs.
• Persistent sandboxes: Learn when agents need filesystem state, long-running environments, and attached storage.
• Best platforms for high-concurrency sandbox environments: Compare orchestration and scaling for large sandbox fleets.
• Ephemeral sandbox environments: Understand short-lived execution environments and lifecycle tradeoffs.
• Alternatives to Vercel for enterprise apps and agents: Compare infrastructure control, GPUs, governance, and BYOC for enterprise workloads.