Which is better, Vercel Sandbox or Blaxel?
It depends on idle time and where your app runs. Whether the code waits or works, Runtime has the lowest bill: $0.64 for the job below, against $2.12 on Vercel and $3.45 on Blaxel. Runtime also keeps memory through a pause. Pick Vercel Sandbox if your app is on Vercel or needs one of 19 regions. Pick Blaxel for fleets of over 100,000 sandboxes on its top tier, or for standby after 15 seconds with a resume in about 25 ms.
At a glance
Vercel's figures are at the rates of its default iad1 region.
| Vercel Sandbox | Blaxel | Runtime | |
|---|---|---|---|
| Isolation | Firecracker microVM, own kernel | Lightweight virtual machines | Firecracker microVM, own kernel |
| CPU | $0.128 per active CPU-hour | Included with memory; 8 GB gets 4 cores | $0.025 per vCPU-hour of measured CPU, with a small floor |
| Memory | $0.0212 per provisioned GB-hour; 2 GB per vCPU | $0.0000115 per GB-second of active time, $0.0414 an hour | $0.0075 per reserved GiB-hour |
| Plan fee | Hobby allowance free; usage beyond it needs Pro | None; tiers grow with credit added | None; prepaid credit from $10 |
| Free start | 5 active CPU-hours and 420 GB-hours a month on Hobby | Up to $200 of credit | 100 free hours of a 1 GB machine in the first 30 days, no card |
| When idle | Runs until its timeout or stop() |
Standby about 15 seconds after the last connection closes | Pauses after the idle time you set; wakes on the next request |
| Kept while idle | The filesystem; processes start again | Files and processes, in a $0.20 per GB-month snapshot | Files, memory and processes, $0.08 per GB-month |
| Concurrency | 10 on Hobby, 10,000 on Pro | Over 100,000 on the top tier | 4 without credit, 100 paid, raised on request |
When is Blaxel cheaper than Vercel?
When the code is busy. Blaxel's price depends only on memory and time. CPU comes with the memory, so a 4 GB sandbox costs $0.1656 an hour whether its cores are idle or at full load. Vercel bills memory at about half Blaxel's rate, which is $0.0848 an hour for 4 GB. It then adds $0.128 for every CPU-hour the code actually uses.
So Vercel wins for agents that wait, and Blaxel wins for agents that compute. For a 2 vCPU, 4 GB sandbox running a minute, the line falls at about 57 CPU-seconds of the 120 available. Below that, Vercel is cheaper. Above it, Blaxel is. With both CPUs busy the whole minute, Vercel costs about half as much again.
Blaxel's other difference is sizing. It sets CPU from memory, 4 cores for 8 GB, so a CPU-heavy job cannot take more cores without paying for more memory. Vercel gives 2 GB per vCPU. Runtime sizes vCPUs and memory apart.
What does idle time cost?
Blaxel's standby is its strongest feature. A sandbox goes to standby by itself
about 15 seconds after its last connection closes. It pays nothing for compute
there, and it resumes in about 25 ms, as Blaxel states it. The standby snapshot
costs $0.20 per GB a month. A Vercel sandbox keeps billing until its timeout
or stop(), and a stopped one starts its processes again.
Runtime pauses a sandbox after 300 seconds with nothing happening in it, or after the idle time you set. It keeps memory and processes at $0.08 per GB a month, and it wakes on the next request:
TypeScriptimport { Sandbox } from "withruntime";const sbx = await Sandbox.create({ idlePauseSeconds: 60 });await sbx.files.write("/workspace/task.txt", "step 1 done\n");// A minute with no requests pauses it. This read wakes it first:console.log(await sbx.files.readText("/workspace/task.txt"));await sbx.stop();Cost for the same job
1,000 runs of a 2 vCPU sandbox with 4 GiB, or 4 GB on Vercel and Blaxel. Each run lasts 60 seconds and keeps the CPU busy for 20 CPU-seconds: an agent that mostly waits for a model.
- CPU
- 1,000 × 20 s / 3,600 × $0.128
- $0.71
- Memory
- 1,000 × 60 s / 3,600 × 4 × $0.0212
- $1.41
- Memory
- 1,000 × 75 s × 4 × $0.0000115
- $3.45
- CPU
- 1,000 × 20 s / 3,600 × $0.025
- $0.14
- Memory
- 1,000 × 60 s / 3,600 × 4 × $0.0075
- $0.50
At 100,000 runs a month, the cost is $212.44 on Vercel, $345.00 on Blaxel and $63.89 on Runtime. With both CPUs busy for the whole minute, it is $1.33 on Runtime, against $5.68 on Vercel and $3.45 on Blaxel. Runtime is cheaper however busy the sandbox is. The Blaxel figure includes the 15 seconds or so each sandbox stays billed after its run, before standby. Plan fees, creations, snapshot storage, network and free credit are left out.
Which one to pick
- Pick Vercel Sandbox if your app is on Vercel, or you need a sandbox in a region you choose, from 19.
- Pick Blaxel for very large fleets, with over 100,000 sandboxes running at the same time on its top tier, or for a standby that begins 15 seconds after the last connection and resumes in about 25 ms.
- Pick Runtime for the lowest bill at any level of use, with CPU and memory sized apart, and paused sandboxes kept with their memory at $0.08 per GB a month while you have credit.
Switch from either one
From Vercel Sandbox, one import changes and the code stays, with no Vercel project or token:
TypeScriptimport { Sandbox } from "withruntime/vercel"; // was: from "@vercel/sandbox"Pythonfrom withruntime.vercel import sandbox # was: from vercel import sandboxBlaxel's sandbox SDK has its own drop-in: import SandboxInstance from
withruntime/blaxel rather than @blaxel/core, or in Python from
withruntime.blaxel rather than blaxel.core. Standby needs no code: a
request to a paused Runtime sandbox wakes it by default, and idlePauseSeconds
sets when it pauses. The table in migration
maps each call if you port to Runtime's own SDK.
Or give your coding agent the one instruction in migration. It switches the project on a branch, tests it on the free usage and reports the monthly saving. Credit you add within 30 days of signing up is matched, up to $1,000 in total. The full side-by-sides are Runtime vs Vercel Sandbox and Runtime vs Blaxel.
Runtime Cloud
Runtime runs the same job for 70% less than Vercel and 81% less than Blaxel. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $2.12 on Vercel, $3.45 on Blaxel and $0.64 on Runtime. Runtime bills measured CPU and reserved memory as two meters, both below either rival's rate. So it stays cheapest whether the code waits or works. Rates checked 25 October 2026.
Run npx withruntime login to use the free usage. To switch Vercel
Sandbox or Blaxel code, see the migration guide.
Sources
Vercel Sandbox rates checked 25 October 2026 and its pricing rechecked 25 October 2026. Blaxel rates checked 25 October 2026, with its pricing page and sandbox documentation.
- Vercel Sandbox pricing, Understanding Vercel Sandboxes
- Blaxel pricing, Blaxel sandboxes
- Runtime pricing
Facts on this page were checked on 26 October 2026.