Blaxel vs Northflank Northflank is 68% cheaper per agent run

Which is better, Blaxel or Northflank?

It depends on how busy your sandboxes are. For agents that mostly wait on a model, Runtime has the lowest cost: $0.64 for the typical run, against $1.11 on Northflank and $3.45 on Blaxel. Runtime bills the CPU a run spends, not the CPUs it holds. Pick Northflank when every CPU stays busy, because its allocated rate comes out below Runtime's. Pick Northflank also for GPUs billed by the second, or to run in your own AWS, GCP or Azure account. Pick Blaxel for a resume under 25 ms.

At a glance

Standby or always on: which is cheaper?

It depends on how much of the day the sandbox works. A 2 vCPU, 4 GB service on Northflank costs $0.0667 an hour, billed by the second while it runs. Northflank presents running for weeks as a feature ("No time limits"). Its free Sandbox plan is "Always on, no sleeping".

Blaxel charges $0.1656 an hour for 4 GB while the sandbox is active, about two and a half times as much. Once the sandbox is on standby, it charges nothing for compute. Standby starts about 15 seconds after the last connection closes. Standby costs snapshot storage, $0.20 per GB-month. On compute alone, Blaxel is the cheaper of the two when a sandbox is active for less than about 40% of the hours Northflank would keep it running.

Runtime does both. A waiting sandbox is billed only the CPU floor, a twentieth of a vCPU. So 2 vCPU and 4 GiB costs $0.03125 an hour while it waits on a model, 53% below Northflank's figure. Set idlePauseSeconds and it pauses itself, keeping memory and processes for $0.08 per GB-month. The next request wakes it.

Cost for the same job

1,000 runs of a 2 vCPU, 4 GiB sandbox (4 GB on Blaxel and Northflank). Each run lasts 60 seconds and keeps the CPU busy for 20 CPU-seconds: an agent that mostly waits for a model.

At 100,000 runs a month, that is $345.00 on Blaxel, $111.10 on Northflank and $63.89 on Runtime. With both CPUs busy for the whole minute, it is $1.11 on Northflank, below $1.33 on Runtime, and $3.45 on Blaxel. Northflank's allocated rate wins when every CPU works all the time. The Blaxel figure includes the 15 seconds or so each sandbox stays billed after its run, before standby. Storage, network, taxes and free allowances are left out.

How do they isolate code?

Northflank states that its sandboxes run in Cloud Hypervisor microVMs for CPU workloads and in gVisor for GPU workloads. Blaxel describes its sandboxes as lightweight virtual machines and does not name the hypervisor. Runtime gives every sandbox a Firecracker microVM with its own Linux kernel. See Cloud Hypervisor vs Firecracker and Firecracker vs gVisor for how those boundaries differ.

Which one to pick

• Pick Blaxel if your sandboxes are idle most of the time and must come back fast. Blaxel states a resume in under 25 ms, and its top tier runs over 100,000 sandboxes at the same time.
• Pick Northflank for sandboxes that run for days with every CPU busy, for GPUs (L4, A100 and H100, billed by the second), or to run in your own AWS, GCP or Azure account.
• Pick Runtime for agents that wait on a model. Measured CPU makes the typical run 42% cheaper than Northflank and 81% cheaper than Blaxel. A sandbox is one call. Pauses and forks keep memory.

Switch from either one

Blaxel's SDK has a drop-in on Runtime. Import SandboxInstance from withruntime/blaxel (Python withruntime.blaxel), and the calls stay. Northflank has none. Its calls map directly (map the calls). A sandbox service with its deployment plan becomes one create call with the size you want:

TypeScriptimport { Sandbox } from "withruntime";const box = await Sandbox.create();try {  await box.files.write("/workspace/task.py", "print(sum([125, 250, 375]))\n");  console.log((await box.exec("python3 /workspace/task.py", { check: true })).stdout);} finally {  await box.stop();}

Pythonfrom withruntime import Sandboxwith Sandbox.create() as box:    box.files.write("/workspace/task.py", "print(sum([125, 250, 375]))\n")    print(box.exec("python3 /workspace/task.py", check=True).stdout)

Or give your coding agent the one instruction in migration. It switches the project on a branch, tests it on free usage, and reports the monthly saving. npx withruntime compare --from northflank (or --from blaxel) prices what you ran at the old provider's rates. 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 Blaxel and Runtime vs Northflank.

Sources

Northflank rates checked 25 October 2026, and its pricing and sandbox pages reread 26 October 2026. Blaxel rates checked 25 October 2026, with its pricing page and sandbox documentation.

• Blaxel pricing, Blaxel sandboxes
• Northflank pricing, Northflank sandboxes, Sandboxes on Northflank
• Runtime pricing and security

Facts on this page were checked on 26 October 2026.