CodeSandbox review

CodeSandbox is a hosted sandbox service with APIs for creating isolated development environments. It sits alongside an application or AI-agent backend: your system provisions a sandbox, runs code inside it, then manages or shuts down the environment. The vendor positions it for code execution, development environments, evaluations and CI/CD, including workloads that run untrusted code.

The product is not just a browser-based editor. Its homepage describes microVM infrastructure, concurrent virtual machines, snapshots and automatic hibernation. Those features target backend execution and resumable environments as well as interactive development. The vendor says snapshots preserve a sandbox across periods of inactivity and that VMs can be started, cloned and restored from snapshots within two seconds. It also claims capacity for millions of concurrent VMs; treat that as a vendor scale claim, not a workload-specific guarantee. CodeSandbox is now part of Together AI, and the homepage presents the SDK as a way to bring code interpretation to generative AI.

The integration surface is the CodeSandbox API and SDK. The homepage says the APIs create isolated sandboxes and identifies the CodeSandbox SDK, including full SDK access on the Scale plan. That gives application code a way to provision execution environments rather than asking your team to operate the isolation layer itself. The homepage does not name a wire protocol, programming language, CLI or framework integration, so confirm the SDK’s supported languages and API operations in the vendor’s documentation before choosing it for a stack.

The advertised workflows include giving AI agents sandboxes, running multiple agents in parallel, forking environments for A/B tests, creating developer or student workspaces, interpreting untrusted code, running evaluations and executing CI/CD tests. Snapshots and custom hibernation are relevant when environments need to resume without staying active. The homepage links to learning more about the SDK, but does not identify specific SDK packages or document compatibility details there. Check the docs for authentication, lifecycle calls, error handling and limits for your intended integration.

Build is free and includes up to five members, 40 VM-credit hours monthly (400 credits), up to 10 concurrent VMs and VMs with up to 4 vCPUs and 8 GiB RAM. It also includes unlimited Browser and VM Sandboxes/Devboxes, but the VM-hour and concurrency caps constrain compute-heavy use.

Pro costs $12 per workspace monthly, or $9 per workspace monthly with annual billing. It supports up to 20 members, starts at 100 VM-credit hours monthly and allows VMs up to 16 vCPUs and 32 GiB RAM. Scale (Builder) costs $170 per workspace monthly, or $119 with annual billing. It starts at 160 VM-credit hours (1,100 credits), includes 100–250 concurrent VMs and 10,000 hourly SDK requests, and provides full SDK access.

Pro and Scale list on-demand VM credits at $0.15–$0.18 per hour ($0.01486–$0.015 per credit), so sustained execution can add to the workspace fee. Enterprise pricing is custom, with custom credit allocations and concurrency. The pricing page lists bulk Enterprise credit packs at up to 50% off.

CodeSandbox is offered as a hosted service, and the vendor does not publish an open-source license for the current product in its homepage material. An older Reddit discussion about the project’s browser editor includes its creator saying it was not open source at that time; that comment is not a current licensing statement for the SDK or service.

Enterprise lists on-premise and private managed cloud options, so self-managed deployment is an enterprise conversation rather than a published general-purpose self-hosting route. The vendor does not publish a data-export or migration procedure on the homepage. Before adoption, ask how to retrieve source files, snapshots, logs and configuration, and whether those exports can run outside CodeSandbox. The more your workflow depends on its SDK, VM lifecycle and snapshot behavior, the more migration work you should plan for.

The vendor says environments isolate untrusted code and claims the platform can handle millions of concurrent VMs, with VM startup, cloning and snapshot restore within two seconds. Those are useful design targets, but a production review should confirm isolation boundaries, quotas, service-level commitments and behavior under your workload. Enterprise lists SOC 2 Type II compliance, dedicated support, SSO and custom VM allocations; the other plans have lower published concurrency and resource limits.

Model compute use against VM-credit hours, concurrency and, on Scale, the 10,000 hourly SDK request allowance. Confirm what happens when a workload exceeds its plan limits, how hibernation affects active jobs and how snapshots are retained. Reddit discussions about CodeSandbox include praise for sharing and forking browser projects, but those comments concern the editor experience rather than current SDK operations. One Reddit thread also describes custom NPM registry configuration for downloaded projects. Validate package access and your own recovery path before relying on the service for production builds.