Mitos vs CodeSandbox
Mitos and the CodeSandbox SDK both fork a running microVM into copies. Mitos lands a warm fork in about 27 ms, ships under Apache 2.0, and runs on your own Kubernetes cluster; CodeSandbox is closed and hosted only.
CodeSandbox is one of the few runtimes that also forks a running VM, so the fork itself is a tie. The difference is speed, openness, and ownership: Mitos activates a warm fork in about 27 ms against the hundreds of milliseconds CodeSandbox publishes, ships under Apache 2.0, and self-hosts on any KVM Kubernetes cluster, while CodeSandbox stays a closed, hosted SDK.
Mitos vs CodeSandbox, capability by capability
Capabilities from each project's public docs as of June 2026, not a head-to-head benchmark. Numbers move; the source of truth is each project's own repo and docs.
| Capability | Mitos | CodeSandbox |
|---|---|---|
| Fork a running VM (memory + processes) | ✓ memory + processes | ✓ ~863 ms fork |
| Warm activate latency | ✓ ~27 ms activate | ◐ ~495 ms resume |
| Published marginal cost per fork | ✓ ~3 MiB / fork | ✗ |
| microVM isolation (own kernel) | ✓ Firecracker microVM, KVM | ✓ Firecracker |
| Open source license | ✓ Apache 2.0 | ✗ closed, hosted |
| Self-host on your cluster | ✓ any KVM K8s | ✗ hosted only |
What sets Mitos apart
The same fork, far faster
Mitos and CodeSandbox both fork a running microVM rather than rebuild each from scratch, so the fork is not ours alone. The difference is speed: Mitos lands a warm fork in about 27 ms, while CodeSandbox publishes hundreds of milliseconds.
Open and self-hostable
Mitos ships under Apache 2.0 and runs on any Kubernetes cluster with KVM nodes, so the same engine runs in your account or ours and your data never leaves your infrastructure. The CodeSandbox SDK is closed and hosted, so it stays on their cloud.
A primitive, not a silo
Mitos exposes the fork as a declarative Kubernetes primitive, with CRDs and a published per-fork memory cost of about 3 MiB, so you build your own agent platform on top. CodeSandbox wraps the same fork inside its own closed hosted SDK.
Why teams pick Mitos over CodeSandbox
- The same live fork, but a warm activate in about 27 ms instead of hundreds.
- Apache 2.0 and self-hostable on any KVM Kubernetes cluster, not a closed hosted SDK.
- A declarative microVM primitive with a published per-fork memory cost, built for your own platform.
Mitos vs CodeSandbox, in brief
Does CodeSandbox fork a running sandbox?
Yes. CodeSandbox is one of the few runtimes that forks a running microVM from a memory snapshot. Mitos does the same, but activates a warm fork in about 27 ms and publishes the per-fork memory cost.
Can I self-host CodeSandbox?
No. The CodeSandbox SDK is closed and hosted only. Mitos is Apache 2.0 and runs on any Kubernetes cluster with KVM nodes, or fully hosted on the same engine.
Which is faster?
Mitos publishes about 27 ms to activate a warm fork, against the hundreds of milliseconds CodeSandbox publishes for live fork and memory resume. Both are self-reported on different hardware, so treat it as context, not a head-to-head benchmark.