Which is better, CodeSandbox or AWS Lambda MicroVMs?
It depends on how big the machine must be and where it must run. For agent runs that mostly wait on a model, Runtime has the lowest bill: $0.64 for the benchmark against $2.48 on CodeSandbox and $4.20 on Lambda, billed per second for runs of any length. Pick the CodeSandbox SDK for very large VMs, up to 64 cores, and its browser development tooling; pick Lambda MicroVMs for sandboxes inside AWS.
At a glance
| CodeSandbox SDK | AWS Lambda MicroVMs | Runtime | |
|---|---|---|---|
| Isolation | Firecracker microVM | Firecracker microVM | Firecracker microVM, own kernel |
| Price | Nano (2 cores, 4 GB) $0.1486 an hour in credits | $0.2522 an hour for 2 vCPUs and 4 GB | Measured CPU and reserved memory |
| Billing | By the minute, rounded up | By the second | By the second |
| Largest | 64 cores and 128 GB | A 4 vCPU, 8 GB baseline | 16 vCPUs and 64 GiB, paid |
| Snapshots | Memory snapshot and restore | Suspend with memory, up to 8 hours | Pause and forks keep memory and processes |
| Plan | Build free with 10 VMs; Scale $170 a month | None | None; prepaid credit from $10 |
Sizes, not meters
Both sell a shape by the time it exists. CodeSandbox's Nano is 41% cheaper per hour than Lambda's 2 vCPU, 4 GB baseline, but it rounds each run up to the minute, so a 10-second run pays for sixty. Lambda bills to the second. Runtime bills to the second as well, and only for CPU actually used.
Cost for the same job
2 cores and 4 GB, 60 seconds a run, 20 CPU-seconds of work, 1,000 runs:
- Size
- 1,000 × 60 s / 3,600 × $0.1486
- $2.48
- CPU
- 1,000 × 60 s × 2 × $0.0000276944
- $3.32
- Memory
- 1,000 × 60 s × 4 × $0.0000036667
- $0.88
- CPU
- 1,000 × 20 s / 3,600 × $0.025
- $0.14
- Memory
- 1,000 × 60 s / 3,600 × 4 × $0.0075
- $0.50
Busy or idle makes no difference to either rival: with both CPUs busy for the whole minute it is $2.48 on CodeSandbox and $4.20 on Lambda, and $1.33 on Runtime.
Which one to pick
- CodeSandbox SDK for very large VMs, up to 64 cores, and its browser development tooling.
- Lambda MicroVMs for sandboxes inside AWS.
- Runtime for agent runs of any length billed to the second at the lowest rate.
See Runtime vs CodeSandbox and Runtime vs AWS Lambda MicroVMs.
Runtime Cloud
On Runtime the same benchmark costs $0.64, 74% below CodeSandbox and 85% below Lambda MicroVMs. It is 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox (a Nano VM on CodeSandbox) with 20 CPU-seconds of work each.
Use npx withruntime login to start on the monthly free usage. The migration guide explains moving existing sandbox code.
Sources
CodeSandbox rates checked 25 October 2026; Lambda MicroVMs rates checked 25 October 2026.
- Together: CodeSandbox SDK, CodeSandbox SDK pricing
- AWS Lambda pricing, Lambda MicroVMs
- Runtime pricing
Facts on this page were checked on 26 October 2026.