CodeSandbox vs Runloop: pricing, isolation and limits

CodeSandbox bills a fixed VM size per minute; Runloop bills a devbox's CPU, memory and disk per hour. A 2 CPU, 4 GB job: $2.48 vs $5.33.

Runtime costs 74% less than CodeSandbox and 88% less than Runloop for this job, and its image builds are free. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox are $2.48 on CodeSandbox, $5.33 on Runloop and $0.64 on Runtime. Neither rival meters the CPU a run actually spends; Runtime does, second by second. Rates checked 23 September 2026.

At a glance

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

	CodeSandbox SDK	Runloop	Runtime
Isolation	Firecracker microVM	microVM, with a container inside	Firecracker microVM, own kernel, every sandbox
How size is billed	Credits per VM size, $0.01486 a credit	$0.108 per CPU-hour, $0.0252 per GB-hour, disk per GB-hour	$0.025 per vCPU-hour of measured CPU, with a small floor
2 CPU, 4 GB, an hour	$0.1486 (Nano, 10 credits)	$0.3195 (MEDIUM, with 8 GB disk)	$0.03125 waiting, $0.08 fully busy
Billing step	By the minute, rounded up	While initializing, running, suspending or resuming	By the second, no one-minute minimum
Prepared environments	Templates from a snapshot, made with the CLI	Blueprints; a build is $0.252 an hour	Custom images; building is free
Idle	Hibernate and resume	Suspend keeps the disk; processes restart; Pro plan	Pause keeps files, memory and processes, 1 to 365 days
Plan fee	Build free; Scale $170 a month	Basic free; Pro $250 a month plus usage	None; prepaid credit from $10
Free start	The free Build plan, 10 VMs at once; 250 on Scale	$50 of credit, no card; 3 devboxes running at once	50 sandbox hours, no card; eight at once

What does a 2 CPU, 4 GB machine cost an hour?

The two price the same shape very differently.

• CodeSandbox Nano, 2 cores and 4 GB, is 10 credits an hour at $0.01486 a credit: $0.1486. Each VM's time is rounded up to the next minute.
• Runloop MEDIUM, 2 CPUs, 4 GB and 8 GB of disk, is listed at $0.3195 an hour: $0.216 for CPU, $0.1008 for memory and the rest for disk. Compute is billed only while the devbox is initializing, running, suspending or resuming.

So Runloop costs a little over twice as much as CodeSandbox for a machine that runs the whole hour. Runtime charges $0.08 for that hour with both CPUs busy and $0.03125 while the sandbox waits on a model, since only measured CPU is billed above a floor of a twentieth of a vCPU.

Cost for the same job

Now as a job: 1,000 runs of 60 seconds, a Nano VM on CodeSandbox, a MEDIUM devbox on Runloop and 2 vCPU with 4 GiB on Runtime. In each run the code is busy for 20 CPU-seconds and waits out the rest, as an agent does between model calls.

TextCodeSandbox  Size   1,000 × 60 s / 3,600 × $0.1486          = $2.48Runloop      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

Scaled to 100,000 runs a month: $247.67 on CodeSandbox, $532.56 on Runloop, $63.89 on Runtime. If both CPUs are busy for the whole minute, the job costs $1.33 on Runtime, $2.48 on CodeSandbox and $5.33 on Runloop, the two rivals unchanged because they bill the machine rather than the work. The totals omit plan fees, blueprint builds, idle storage, network, taxes and free credit.

Which one to pick

• CodeSandbox when people, not only agents, use the environments: it is built for browser-based development, clones quickly from memory snapshots, and offers fixed machines as large as 64 cores and 128 GB.
• Runloop when the product is benchmarking agents. It runs SWE-Bench and other public suites, builds custom ones from your data, can be deployed into your own cloud account, and states SOC 2, HIPAA and GDPR readiness.
• Runtime when you want a Firecracker microVM per sandbox at 74% below CodeSandbox and 88% below Runloop, image builds at no charge, a pause that keeps memory and running processes, and no plan fee. It runs benchmarks as well; see agent evals and SWE-bench.

Porting templates and blueprints

There is no compatibility import for either SDK, but the calls line up one to one (map the calls). What each calls a template or a blueprint, Runtime calls a custom image: build it once, then start sandboxes from it:

TypeScriptimport { Runtime } from "withruntime";const runtime = new Runtime();await runtime.images.build({ name: "data", recipe: { pip: ["pandas"], apt: ["jq"] } });await using sbx = await runtime.sandboxes.create({ image: "data" });console.log((await sbx.exec("python3 -c 'import pandas; print(pandas.__version__)'")).stdout);

Pythonfrom withruntime import Runtimeruntime = Runtime()image = runtime.images.build(name="data", recipe={"pip": ["pandas"], "apt": ["jq"]})with runtime.sandboxes.create(image=image["id"]) as sbx:    print(sbx.exec("python3 -c 'import pandas; print(pandas.__version__)'").stdout)

An image can also start from a Dockerfile (custom images). To see the saving on your own usage first, npx withruntime compare --from runloop or --from codesandbox reprices what you ran at the old rates, and the migration instruction lets a coding agent do the port on a branch against the free trial. Details: Runtime vs CodeSandbox, Runtime vs Runloop.

Sources

Rates checked 23 September 2026. Together's Code Sandbox documentation, Runloop's pricing page and its devbox sizes reread 25 September 2026.

• Together Code Sandbox, CodeSandbox SDK pricing
• Runloop pricing, Devbox sizes, Devbox lifecycle
• Runtime pricing and custom images

Facts on this page were checked on 25 September 2026.