Runtime

Blaxel vs CodeSandbox: pricing, standby and limits

Blaxel bills memory per second of active time with CPU included; CodeSandbox bills fixed VM sizes by the minute. Both hibernate idle VMs.

Runtime runs the same job for 77% less than Blaxel and 74% less than CodeSandbox. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $2.76 on Blaxel, $2.48 on CodeSandbox and $0.64 on Runtime, because Runtime bills the CPU your code uses and prices memory separately. Its paused storage costs less than Blaxel's standby snapshots, and nothing is rounded up to the minute. Rates checked 23 September 2026.

Estimated compute cost

77% less than Blaxel74% less than CodeSandbox

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, Together Code Sandbox). Plan fees, network, taxes and free credits are left out. The worked example below shows the arithmetic.

At a glance

CodeSandbox's figures come from Together's documentation of the CodeSandbox SDK; CodeSandbox is a Together company.

Blaxel CodeSandbox SDK Runtime
Isolation Lightweight virtual machines Firecracker microVM Firecracker microVM, own kernel
CPU Included with memory; 8 GB gets 4 cores, 16 GB gets 6 Inside a fixed VM size $0.025 per vCPU-hour of measured CPU, with a small floor
Memory $0.0000115 per GB-second of active time Inside the size: Nano is 2 cores and 4 GB, $0.1486 an hour $0.0075 per reserved GiB-hour
Billing unit Per second of active time By the minute, rounded up By the second
Idle Standby about 15 seconds after connections close Hibernates after the session disconnects Pauses after the idle time you set
Resume Under 25 ms, in Blaxel's words From a memory snapshot in three seconds, in Together's Usually about half a second
Idle storage $0.20 per GB-month Not stated in the pages read $0.08 per GB-month
At once 10 free; 50 at $20 a month of top-ups; 200 at $50 10 on the free Build plan; 250 on Scale, $170 a month 100 sandboxes on a paid account to start
Free start Up to $200 of credit The free Build plan 50 sandbox hours, no card

Which one scales to zero better?

Both stop billing compute when nobody is connected, and they differ in how fast and how finely.

Blaxel is the quicker of the two. A sandbox goes to standby about 15 seconds after its last connection closes, and Blaxel snapshots its filesystem and running processes. Reconnecting resumes it in under 25 ms, by Blaxel's account. Its standby snapshots cost $0.20 per GB a month, and connections the sandbox held to outside services time out. Blaxel keeps the writable filesystem in memory, giving it about half of the sandbox's memory.

CodeSandbox hibernates on disconnect and, in Together's words, resumes or clones a VM from a memory snapshot in three seconds. It bills in whole minutes, rounded up, so a VM that runs for 10 seconds pays for a minute.

Runtime pauses on your schedule. Set idlePauseSeconds from 60 to 86,400 and the sandbox pauses when nothing has used it for that long, keeping files, memory and processes. The next request wakes it, usually in about half a second, and it is billed by the second from then. Paused storage is $0.08 per GB a month, kept 1 to 365 days.

Cost for the same job

1,000 runs of a 2 vCPU, 4 GiB sandbox (4 GB on Blaxel). Each run lasts 60 seconds and keeps the CPU busy for 20 CPU-seconds: an agent that mostly waits for a model. On CodeSandbox that is a Nano VM, 10 credits an hour at $0.01486 a credit.

TextBlaxel       Memory 1,000 × 60 s × 4 × $0.0000115       = $2.76CodeSandbox  Size   1,000 × 60 s / 3,600 × $0.1486      = $2.48Runtime      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

At 100,000 runs a month that is $276.00 on Blaxel, $247.67 on CodeSandbox and $63.89 on Runtime. With both CPUs busy for the whole minute, it is $1.33 on Runtime against $2.76 on Blaxel and $2.48 on CodeSandbox, so Runtime is cheaper however busy the sandbox is. Neither rival's price moves with the CPU. The Blaxel figure assumes standby starts the moment a run ends, rather than about 15 seconds later. Plan fees, storage, network and free credits are left out.

Which one to pick

  • Pick Blaxel for sandboxes that must come back in milliseconds with their processes running, or for very large fleets: its top tier runs over 100,000 sandboxes at once.
  • Pick CodeSandbox for large fixed VMs, up to 64 cores and 128 GB, or for 250 VMs at once on its Scale plan.
  • Pick Runtime for the lowest cost of the three, vCPUs and memory chosen apart, per-second billing, and a pause kept for as long as you choose.

Switch from either one

Standby and hibernation become an idle pause, and automatic wake is on by default, so the next request brings the sandbox back:

TypeScriptimport { Sandbox } from "withruntime";const sbx = await Sandbox.create({ funding: "trial", idlePauseSeconds: 60 });await sbx.exec("echo ready > /workspace/state.txt");// Idle for a minute, it pauses; this call wakes it and then runs.console.log((await sbx.exec("cat /workspace/state.txt")).stdout);await sbx.stop();

Or give your coding agent the one instruction in migration: it switches the project on a branch, tests it on the free trial and reports the monthly saving. npx withruntime compare --from blaxel (or --from codesandbox) prices what you ran at the old provider's rates. The full side-by-sides are Runtime vs Blaxel and Runtime vs CodeSandbox.

Sources

Rates checked 23 September 2026; the Blaxel pricing, Blaxel sandbox and Together pages read 25 September 2026.

Facts on this page were checked on 25 September 2026.

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