Cloudflare Sandbox vs Runloop: pricing, isolation and limits

Both run a container inside a VM. Cloudflare bills active CPU from a Worker; Runloop bills every devbox CPU while it runs, and costs more.

Runtime undercuts Cloudflare by 53% and Runloop by 88% on the same job. For 1,000 one-minute runs at 2 vCPU, Cloudflare bills $1.35, Runloop $5.33 and Runtime $0.64. Per vCPU-hour of CPU, that is $0.072 on Cloudflare, $0.108 on Runloop and $0.025 of measured CPU on Runtime, where memory is set to what the job needs. Rates checked 23 September 2026.

At a glance

Cloudflare's figures are Containers rates, the basis for its Sandbox SDK. Runloop's are for its MEDIUM devbox: 2 CPUs, 4 GB and 8 GB of disk.

	Cloudflare Sandbox SDK	Runloop	Runtime
Isolation	A container in its own VM	microVM, with a container inside	Firecracker microVM, own kernel
CPU	$0.072 per active vCPU-hour, metered in 10 ms steps	$0.108 per CPU-hour while the devbox runs	$0.025 per vCPU-hour of measured CPU, with a small floor
Memory	$0.009 per provisioned GiB-hour; at least 3 GiB per vCPU	$0.0252 per GB-hour	$0.0075 per reserved GiB-hour
Disk	$0.000252 per provisioned GB-hour	$0.00034236 per GB-hour	Included while running; paused storage $0.08 per GB-month
Plan fee	Workers Paid, at least $5 a month	Basic free; Pro $250 a month plus usage	None; prepaid credit from $10
Free start	No free tier; the plan includes 375 vCPU-minutes a month	$50 of credit, no card	50 sandbox hours, no card
Idle or suspend	Sleeps after 10 idle minutes by default; files are lost	Suspend keeps the disk; processes restart	Pause keeps files, memory and processes, 1 to 365 days
Called from	A Cloudflare Worker, in TypeScript	Runloop's API	Any backend: API, CLI, MCP server, JavaScript, Python

Both put a container in a VM: how do they differ?

In what the VM is for. Cloudflare runs each sandbox as a container in its own VM, placed by the first request to it across Cloudflare's network. By default it is short-lived: it sleeps after 10 idle minutes by default, and when it stops all its files are deleted, its processes end and its shell state resets.

Runloop runs each devbox as a microVM with a container inside, built to be a coding agent's machine. A devbox keeps its ID, its SSH keys and its disk through suspend and resume, though Runloop's docs say daemons running at suspend time must be restarted by hand. Runloop bills compute while a devbox is initializing, running, suspending or resuming, and bills storage while it is suspended.

A Runtime sandbox is a Firecracker microVM with its own Linux kernel, running Ubuntu 24.04 with Python 3.12, Node.js 24, Bun, git and gcc, and sudo works. For containers of your own, sudo enable-docker runs Docker inside the sandbox. Root inside it still cannot change its network, CPU, memory or cost. See how to run Docker in a sandbox and microVM vs container.

Cost for the same job

The numbers price 1,000 runs, each keeping 2 vCPU for 60 seconds and computing for 20 CPU-seconds of that time. Runloop's MEDIUM has 4 GB, and Runtime is set to 4 GiB. Cloudflare needs 3 GiB or more per vCPU, which puts its 2 vCPU shape at 6 GiB, and its disk is taken as 12 GB, as in Cloudflare's example.

TextCloudflare  CPU    1,000 × 20 s × $0.000020                = $0.40            Memory 1,000 × 60 s × 6 × $0.0000025           = $0.90            Disk   1,000 × 60 s × 12 × $0.00000007         = $0.05            Total                                             $1.35Runloop     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

Run 100,000 of these a month and the bill is $135.04 on Cloudflare, $532.56 on Runloop and $63.89 on Runtime. If both CPUs are busy for the whole minute, it is $1.33 on Runtime, $3.35 on Cloudflare and $5.33 on Runloop; Runloop's total does not change, and Cloudflare stays below it at every load. The Cloudflare total assumes each sandbox is destroyed when its run ends. Left out: plan fees, Workers requests, Durable Object time, storage while suspended, network and free credit.

Which one to pick

• Cloudflare Sandbox: throwaway sandboxes inside a Workers app, on the same account and bindings, started close to users.
• Runloop: benchmarks run for you, SWE-Bench among them or custom ones built from your data, and devboxes deployed into your own cloud account with SOC 2, HIPAA and GDPR readiness.
• Runtime: a coding agent's machine that pauses with processes still running and forks while live, at the lowest rates of the three. To run evaluations yourself, see agent evals and SWE-bench.

Porting from each

On Cloudflare, getSandbox(env.Sandbox, name) maps to Sandbox.getOrCreate(name), sandbox.exec(cmd) to exec, and proxyToSandbox to box.previews.create(port). On Runloop, a devbox becomes a Runtime sandbox; suspend and resume become pause() and wake(), and shutdown becomes stop().

TypeScriptimport { Sandbox } from "withruntime";const box = await Sandbox.create({ funding: "trial" });try {  const result = await box.exec(["python3", "-c", "print(6 * 7)"], { check: true });  console.log(result.stdout);} finally {  await box.stop();}

A coding agent can carry out the port from the single instruction in migration, on a branch, tested on the free trial. Coming from Cloudflare, run npx withruntime switch --from cloudflare before the first top-up to get it matched with credit, up to $100. The longer comparisons are Runtime vs Cloudflare and Runtime vs Runloop.

Sources

Rates checked 23 September 2026; Runloop's devbox lifecycle page and Cloudflare's sandbox lifecycle page read 25 September 2026.

• Cloudflare Containers pricing, Containers limits and instance types, Containers architecture, Sandbox lifecycle
• Runloop pricing, Devbox sizes, Devbox lifecycle, Runloop
• Runtime pricing, sandbox environment

Facts on this page were checked on 25 September 2026.