Runtime

Blaxel vs Runloop: pricing, isolation and limits

Blaxel bills memory only while a sandbox is active; Runloop bills a devbox's CPU, memory and disk while it runs: $2.76 against $5.33.

Runtime beats Blaxel by 77% and Runloop by 88% on the same job, and keeps memory and live processes whenever it pauses. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $2.76 on Blaxel, $5.33 on Runloop and $0.64 on Runtime. Measured CPU on Runtime is $0.025 per vCPU-hour; Runloop charges $0.108 per CPU-hour whether the CPU works or not. Rates checked 23 September 2026.

Estimated compute cost

77% less than Blaxel88% less than Runloop

2 vCPUs · 4 GiB · 60 s a run · 20 CPU-seconds busy

1,000

Compute only, at list rates checked 23 September 2026 (Blaxel pricing, Runloop pricing). Plan fees, network, taxes and free credits are left out. The worked example below shows the arithmetic.

At a glance

Blaxel Runloop Runtime
Isolation Lightweight virtual machines microVM, with a container inside Firecracker microVM, own kernel, every sandbox
CPU Included with memory: 8 GB gets 4 cores $0.108 per CPU-hour while the devbox runs $0.025 per vCPU-hour of measured CPU, with a small floor
Memory $0.0000115 per GB-second of active time $0.0252 per GB-hour $0.0075 per reserved GiB-hour
2 vCPU, 4 GB, an hour $0.1656 while active $0.3195 for a MEDIUM devbox with 8 GB disk $0.03125 waiting, $0.08 fully busy
When idle Standby keeps files and processes Suspend keeps the disk; processes restart Pause keeps files, memory and processes, 1 to 365 days
Idle storage $0.20 per GB-month of snapshot Billed per GB-hour of storage $0.08 per GB-month
Plan fee None; tiers grow with credit added Basic free; Pro $250 a month plus usage, needed to suspend None; prepaid credit from $10
Free start Up to $200 of credit $50 of credit, no card; 3 devboxes running at once 50 sandbox hours, no card

Which one keeps a process running across a pause?

This is where the two differ most for an agent that works in bursts.

  • Blaxel moves a sandbox to standby about 15 seconds after its last connection closes and keeps its files and processes there. It states a resume in under 25 ms, and charges no compute while on standby.
  • Runloop writes a suspended devbox to disk and nothing more. Whatever was running, a dev server, a REPL or a tool call halfway through, has to be started again after resume. Runloop lists suspend and resume under its Pro plan, $250 a month.

Runtime keeps memory and running processes on every pause, with no plan needed, for 1 to 365 days on a paid account at $0.08 per GB-month. A request to a paused sandbox wakes it by itself, and a fork copies a running sandbox with its memory, one to ten copies at once.

Cost for the same job

The job: 1,000 runs, 60 seconds each, 20 CPU-seconds of work, on 2 vCPU with 4 GiB. Blaxel sets CPU from memory, so it is sized at 4 GB. Runloop's MEDIUM devbox matches with 2 CPUs and 4 GB, and brings 8 GB of disk.

TextBlaxel   Memory 1,000 × 60 s × 4 × $0.0000115          = $2.76Runloop  CPU    1,000 × 60 s / 3,600 × 2 × $0.108       = $3.60         Memory 1,000 × 60 s / 3,600 × 4 × $0.0252      = $1.68         Disk   1,000 × 60 s / 3,600 × 8 × $0.00034236 = $0.05         Total                                             $5.33Runtime  CPU    1,000 × 20 s / 3,600 × $0.025           = $0.14         Memory 1,000 × 60 s / 3,600 × 4 × $0.0075      = $0.50         Total                                             $0.64

A month of 100,000 runs costs $276.00 on Blaxel, $532.56 on Runloop and $63.89 on Runtime. With both CPUs busy for the whole minute, it is $1.33 on Runtime, $2.76 on Blaxel and $5.33 on Runloop. Blaxel's number assumes each sandbox enters standby the moment its run ends. Plan fees, idle storage, network, taxes and free credit are not included.

Which one to pick

What you are building Best fit
Bursty sandboxes that must resume in milliseconds, processes intact Blaxel
A fleet above 100,000 sandboxes at once (its top tier) Blaxel
Benchmark runs done for you, SWE-Bench or your own suites Runloop
Devboxes inside your own cloud, with SOC 2, HIPAA and GDPR readiness Runloop
A microVM per sandbox at the lowest price, pause with memory, no plan fee Runtime

Runtime's price here is under a quarter of Blaxel's and under an eighth of Runloop's. It runs benchmarks too; see agent evals and SWE-bench.

Moving a paused workflow over

No compatibility import exists for either SDK, so the port follows map the calls. From Blaxel, SandboxInstance.create() is Sandbox.create(), delete() is stop(), and standby is covered by automatic wake, which is on by default. From Runloop, suspend and resume are pause() and wake(), with the difference that the processes survive:

TypeScriptimport { Sandbox } from "withruntime";const sbx = await Sandbox.create({ timeoutSeconds: 600 });await sbx.spawn("python3 -m http.server 8000", { cwd: "/workspace" });await sbx.pause(); // memory and files are kept; compute billing stopsconst again = await Sandbox.connect(sbx.id);await again.wake({ timeoutSeconds: 1200 }); // the server is still runningawait again.stop();
Pythonfrom withruntime import Sandboxsbx = Sandbox.create(timeout_seconds=600)sbx.spawn("python3 -m http.server 8000", cwd="/workspace")sbx.pause()  # memory and files are kept; compute billing stopsagain = Sandbox.connect(sbx.id)again.wake(timeout_seconds=1200)  # the server is still runningagain.stop()

Before changing anything, npx withruntime compare --from runloop or --from blaxel reprices your recent usage at Runtime's rates. A coding agent can then run the one migration instruction, which ports the project on a branch and tests it on the free trial. More: Runtime vs Blaxel, Runtime vs Runloop.

Sources

Rates checked 23 September 2026. Both pricing pages, Blaxel's sandbox documentation and Runloop's devbox sizes reread 25 September 2026.

Facts on this page were checked on 25 September 2026.

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