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Alternatives

Railway Sandboxes alternatives

Answer in brief

The 6 alternatives below are grouped by kind of sandbox, and each says what it does differently from Railway Sandboxes. Start from whatever made you look: missing GPUs, session limits, self-hosting, pricing or isolation.

By the Agent Sandboxes editors · Updated

Why teams look beyond Railway Sandboxes

The natural sandbox for teams already deploying on Railway, strongest when agents need private-network access to existing services.

  • No pause/resume; idle sandboxes are destroyed, and memory continues to bill while idle
  • Hypervisor and compliance are not documented on the sandbox pages
  • No egress allow-list; outbound internet is always on
  • Free and Trial sandboxes are limited to 2 vCPU/2 GB and a 5-minute idle timeout

Railway Sandboxes alternatives, by kind

Hosted sandbox platforms

SDK-driven sandboxes you create, run code in and destroy through an API.

  • 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

    How it differs: 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.

    Full profile →Vercel Sandbox alternativesWebsite ↗

Persistent VMs and agent computers

Full, long-lived virtual machines that an agent keeps, forks and returns to.

  • 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

    How it differs: Long-running, stateful agent computers that should cost nothing while idle. The most natural “persistent computer per agent” model, with idle-free billing.

    Full profile →Fly.io Sprites alternativesWebsite ↗

Compute platforms with sandboxes

General serverless or app platforms that also offer sandboxes, often with GPUs.

  • Depot Sandboxes

    MicroVM sandboxes on the bare-metal compute behind Depot CI, with a TypeScript SDK, Tailscale networking and a Managed Agents service that hosts Claude Code, Codex, Devin and Amp sessions.

    • MicroVM on bare metal
    • BYOC
    • Snapshots

    How it differs: Teams on Depot CI who want agent sandboxes and hosted coding-agent sessions billed from the same minute pool. A sensible add-on for Depot CI customers, less compelling as a standalone sandbox given the file-only snapshots and limited SDK coverage.

    Full profile →Depot Sandboxes alternativesWebsite ↗

  • Koyeb Sandboxes

    Ephemeral microVM sandboxes on Koyeb’s serverless platform for AI-generated code, with CPU or GPU and scale-to-zero.

    • MicroVM
    • GPU

    How it differs: Teams already on Koyeb or in the Mistral ecosystem that want GPU-capable ephemeral sandboxes. Promising GPU-capable microVMs, but still preview — evaluate as it matures within Mistral.

    Full profile →Website ↗

  • Northflank Sandboxes

    Sandboxes on Northflank’s Kubernetes-based platform — microVMs for CPU work, gVisor for GPUs — on Northflank’s cloud or in your own cloud account.

    • Cloud Hypervisor microVM
    • BYOC
    • GPU
    • Pause/resume

    How it differs: Teams that want sandboxes in their own cloud account (BYOC) alongside app hosting, databases and GPUs. Compelling for BYOC and all-in-one platform needs; review the October 2026 incident response before adopting.

    Full profile →Website ↗

Railway Sandboxes vs alternatives

SandboxIsolationOpen sourceSelf-host / BYOCCold start (vendor)Max sessionSnapshots / pauseGPUSDKs
Railway SandboxesLinux VMNoNo / NoNot documentedNo cap (idle 30 min default)Yes / NoNot documentedJavaScript/TypeScript, CLI, GraphQL API
Depot SandboxesMicroVM on bare metalNoNo / YesNot documented2 h default timeoutYes / NoNot documentedJavaScript/TypeScript, CLI
Fly.io SpritesMicroVMNoNo / No0.1–2 s wakeUnlimitedYes / YesNoJavaScript/TypeScript, Go, Python, Elixir
Koyeb SandboxesMicroVMNoNo / Not documentedNot documentedUp to 24 hNot documented / Not documentedYesPython, JavaScript/TypeScript
Modal SandboxesgVisor or VMNoNo / Not documented<1 sUp to 24 hYes / YesYesPython, JavaScript/TypeScript, Go
Northflank SandboxesCloud Hypervisor microVMNoNo / Yes<1 sUnlimitedNot documented / YesYesJavaScript/TypeScript, Python
Vercel SandboxFirecracker microVMNoNo / NoMilliseconds (claim)24 h (Pro)Yes / YesNot documentedJavaScript/TypeScript, Python

Frequently asked questions

What are the main alternatives to Railway Sandboxes?
Depot Sandboxes, Fly.io Sprites, Koyeb Sandboxes, Modal Sandboxes, Northflank Sandboxes, Vercel Sandbox. Which one fits depends on what you need that Railway Sandboxes does not offer; each entry above explains how it differs.
Is there an open-source alternative to Railway Sandboxes?
Among the alternatives listed here, none is fully open source; see the self-hosting guide.

Cite this page

Agent Sandboxes. (2026). Railway Sandboxes alternatives. agentsandboxes.org. Last reviewed November 9, 2026. https://agentsandboxes.org/alternatives/railway-sandboxes/

Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.