CodeSandbox

CodeSandbox is a web and iOS service for programmatically creating development environments that run code. Its SDK is designed to start environments on demand, and each environment runs in isolation for safer execution of untrusted code. MicroVMs can be started, cloned, or restored from snapshots within 2 seconds; snapshots let development resume in the same sandbox after inactivity. Users can set the inactivity period before automatic hibernation. Teams can run agents in parallel without interference, or fork work to A/B test different agents. For CI/CD, tests can run inside sandboxes that hibernate after completion. Sandpack supports live coding in a browser, and integrations include a VS Code extension and a Storybook code playground for every story. CodeSandbox says it can handle millions of concurrent VMs. It offers a free plan. Build, Scale, and Enterprise plans list different member, VM-credit, concurrency, request, and hardware limits, but no prices are stated. The company is headquartered in Amsterdam and is part of Together AI.

CodeSandbox combines isolated development environments with snapshot resume, parallel agents, and CI/CD support.

CodeSandbox suits developers and teams that need isolated, programmatically created environments for code execution, testing, or parallel agent work. Its integrations may also suit users working with browser coding, VS Code, or Storybook.

CodeSandbox is a cloud development environment for running code in isolated sandboxes, with tools for browser-based coding, collaborative agents and automated tests. It suits developers and teams that need repeatable environments or a way to execute untrusted code; its strongest case is fast, resumable sandboxes, while its plan quotas warrant close attention.

Overview

CodeSandbox programmatically creates development environments for immediate code execution. Each environment is isolated, a useful safeguard when running untrusted code. The service says it can handle millions of concurrent virtual machines, though the practical capacity available to a team depends on its plan.

MicroVMs can be started, cloned or restored from snapshots within two seconds. Snapshots let work resume in the same sandbox after inactivity, and users can set how long an environment stays idle before automatic hibernation. Those controls suit workloads that need quick restarts without paying to keep every environment active.

CodeSandbox was founded in 2017 and is headquartered in Amsterdam. CodeSandbox BV is now identified as a Together AI company; the two joined forces on CodeSandbox SDK.

Key features

Parallel agents can work in separate sandboxes without interfering with each other, and forking lets teams compare agents through A/B tests. This is a focused fit for agent development, though the value depends on available VM credits and concurrency.

For continuous integration, tests can run inside sandboxes that hibernate after completion. Prebuilds, persistent storage, GitHub VCS support and devcontainer workspace configuration help make the environments part of a development workflow rather than disposable demos. Deployment options include isolated sandboxes and entire VMs.

Sandpack brings live coding to the browser, while Storybook integration provides a playground for each story. A VS Code extension connects the service to an established editor workflow. Together, these features cover browser demos and team development, but the page does not establish that CodeSandbox replaces a full local development setup for every project.

Pricing

CodeSandbox uses a freemium model with a free plan and free starts and trials. The Build, Scale and Enterprise plans have custom pricing.

• Build: Five members, 40 monthly VM-credit hours, 4 vCPUs and 8 GiB RAM. It is the smallest listed team tier; the 40-hour allowance makes it a better fit for limited workloads than continuous, heavy VM use.
• Scale: 20 members, 160 monthly VM-credit hours, 1,000 new sandboxes per hour, 250 concurrent VMs, 10,000 SDK requests per hour, 16 vCPUs and 32 GiB RAM. Its larger quotas suit teams running parallel work or using the SDK at scale.
• Enterprise: Unlimited members, custom storage and hourly request limits, 64 vCPUs and 128 GiB RAM. It is aimed at organizations that need more compute and tailored limits.

Build and Scale impose member and VM-credit ceilings, while Enterprise removes the member cap but keeps storage and request limits custom.

Platforms

CodeSandbox is available on the web and iOS. Its browser coding features make web access central to the product; the listed platform support does not establish feature parity between web and iOS.

Who it's for

CodeSandbox is a strong fit for developers who need isolated, quickly resumable environments, teams testing multiple agents in parallel, and engineering groups that want CI tests to hibernate after finishing. Browser-based playgrounds also make it relevant for interactive examples and component stories.

It is less compelling for a small team with simple needs if the plan’s VM-hour and concurrency allowances exceed its requirements, or for buyers who need a clear published price before evaluating a paid tier. Its listed plan quotas make capacity planning important for sustained workloads.

Pros and cons

• Pro: Snapshot restoration and VM start, clone and restore times of up to two seconds support fast returns to work after inactivity.
• Pro: Isolated environments, parallel agents and fork-based A/B testing provide a controlled way to run and compare separate code tasks.
• Pro: CI tests can run in sandboxes that hibernate after completion, avoiding the need to keep those environments active between jobs.
• Con: Build and Scale have defined member and VM-credit limits, which can constrain teams with sustained or highly parallel use.
• Con: Paid tiers use custom pricing, making cost comparison harder before contacting the provider.
• Con: The free plan has no stated quota figures, so its suitability for ongoing work is difficult to judge.

Alternatives

Choose ANY.RUN instead if you need a sandbox product with listed support across Android, API, iOS, Linux, macOS, web and Windows; its Community plan is free forever and covers specified Windows, Android and Ubuntu environments.

Hatching Triage is a better fit for analysis-volume licensing, with packages starting at 500 analyses per day and scaling toward 50,000 per day.

For private access rather than development sandboxes, consider Zscaler Private Access, a paid service whose listed tiers include limited private access for a portion of users.

Anthropic Sandbox Runtime is another option for readers seeking a free sandbox runtime.

Context Agent Sandboxes offers a free tier with one agent at a time and a Plus plan at $20 a month per person for three agents at a time; consider it if those agent limits and per-person pricing better match your needs.

crun is a free, Linux and self-hosted OCI container runtime, rather than a cloud development environment.

Choose Docker Desktop if you want a freemium desktop container tool: its free Personal plan includes Docker Desktop, Docker Engine and Kubernetes, Docker Hub, Docker Scout and Docker Debug.

E2B is worth considering if an open-source, self-hostable runtime is a priority; it uses an Apache-2.0 license and its Hobby plan includes a one-time usage credit alongside usage costs.

For broader browsing, see Sandbox Software, Cloud Development Environments, Coding Playgrounds, Web Development IDEs and Code Playground Software.

Verdict

CodeSandbox is a strong choice for developers and teams that need isolated environments they can resume quickly, run agents in parallel and use for hibernating CI tests. Its main drawback is commercial clarity: paid plans have custom pricing, and the listed VM credits and member limits make fit dependent on workload. Choose it for the environment and workflow controls; look elsewhere if predictable published pricing or a different kind of sandbox is the priority.