Which is better, Blaxel or AWS Lambda MicroVMs?
It depends on how long your sandboxes sit idle and where they must run. For an agent that spends most of a run waiting on a model, Runtime has the lowest cost: $0.64 against $3.45 on Blaxel and $4.20 on Lambda. Runtime charges for CPU used, not for vCPUs held, and a pause keeps memory and processes. Pick Blaxel when sandboxes must resume in about 25 ms. Pick Lambda MicroVMs when the work is tied to an AWS account.
At a glance
| Blaxel | AWS Lambda MicroVMs | Runtime | |
|---|---|---|---|
| Isolation | Lightweight virtual machines | Firecracker microVM | Firecracker microVM, own kernel |
| CPU | Included with memory; 8 GB gets 4 cores | $0.0997 per baseline vCPU-hour | $0.025 per vCPU-hour of measured CPU, with a small floor |
| Memory | $0.0000115 per GB-second of active time | $0.0000036667 per GB-second | $0.0075 per reserved GiB-hour |
| Idle | Standby when connections close; resumes in ~25 ms | Suspends after an idle time you set | Pause, or idle pause, keeps memory while you have credit |
| Kept asleep | $0.20 per GB-month snapshot | $0.08 per GB-month, a week minimum | $0.08 per GB-month |
| Free start | Up to $200 of credit | No free tier | 100 free hours of a 1 GB machine in the first 30 days, no card |
How each stops the meter
Blaxel puts a sandbox on standby immediately after its connections close. It
bills nothing for compute in standby. Lambda suspends after an idle time you
set with maxIdleDurationSeconds. Runtime pauses on request, or by itself after 300 seconds with
nothing happening in it (idlePauseSeconds sets the wait). It wakes on the
next command or visit.
Cost for the same job
The benchmark runs 60 seconds a run, with 4 GB of active memory on Blaxel and a 4 GB baseline on Lambda:
- Memory
- 1,000 × 75 s × 4 × $0.0000115
- $3.45
- 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
Neither rival meters CPU use. With both CPUs busy for the whole minute, the cost is still $3.45 on Blaxel and $4.20 on Lambda, against $1.33 on Runtime.
Which one to pick
- Blaxel for sandboxes that sit idle most of the time and must resume in milliseconds.
- Lambda MicroVMs for work tied to an AWS account.
- Runtime for the lowest running cost, with CPU and memory chosen separately, and cheaper storage while paused.
See Runtime vs Blaxel and Runtime vs AWS Lambda MicroVMs.
Runtime Cloud
Runtime costs 81% less than Blaxel and 85% less than Lambda MicroVMs. For 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox using 20 CPU-seconds each, Blaxel costs $3.45, AWS Lambda MicroVMs cost $4.20, and Runtime costs $0.64.
Start on 100 free hours of a 1 GB machine a month with npx withruntime login. Port existing Blaxel or Lambda code with the migration guide.
Sources
Blaxel rates checked 25 October 2026; Lambda MicroVMs rates checked 25 October 2026.
Facts on this page were checked on 26 October 2026.