Daytona vs Fly Machines: pricing, isolation and limits

Daytona is a sandbox API that defaults to containers; a Fly Machine is a Firecracker VM billed by size. The same job costs $2.76 vs $1.44.

Runtime runs the same job for 77% less than Daytona and 55% less than a Fly Machine. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $2.76 on Daytona, $1.44 on a performance-2x Machine and $0.64 on Runtime. Runtime gives every sandbox its own Firecracker microVM, like a Machine, and bills the CPU the code uses rather than the size it holds. Rates checked 23 September 2026.

At a glance

Fly Machines are at the rates of Fly.io's Ashburn (iad) region.

	Daytona	Fly Machines	Runtime
What it is	A sandbox API with SDKs for agents	General-purpose VMs, driven by the Machines API and flyctl	A sandbox API with SDKs for agents
Isolation	Containers by default; VM sandboxes as a separate class	Firecracker microVM	Firecracker microVM, own kernel, every sandbox
Price	$0.0504 per vCPU-hour, $0.0162 per GiB-hour	By size while started: performance-2x, 4 GB, $0.0861 an hour	$0.025 per vCPU-hour of measured CPU, $0.0075 per GiB-hour
Billed	Per second	By the second while a Machine runs	Per second
Disk	First 5 GiB free, then $0.000108 per GiB-hour, stopped or not	Root disk temporary; stopped rootfs $0.15 per GB-month	Included while running; paused storage $0.08 per GB-month
Plan fee	None published	None; pay as you go	None; prepaid credit from $10
Free start	$200 of compute, no card	Not stated on the pricing page	50 sandbox hours, no card
When idle	Stops after 15 idle minutes by default	Billed while started; suspend keeps memory	Pause keeps files, memory and processes, 1 to 365 days
Regions	US and EU	18 regions	One US region

Is a Fly Machine cheaper than a Daytona sandbox?

At list rates, yes. A performance-2x Machine, 2 performance vCPUs kept as whole cores and 4 GB, costs $0.0861 an hour. Daytona's 2 vCPUs and 4 GiB cost $0.1008 plus $0.0648, $0.1656 an hour. Both charge that whether the code is busy or waiting, so the Machine stays about half the price at any load.

Fly also sells shared vCPUs. A shared-cpu-2x Machine with 4 GB costs about $0.50 for the 1,000 runs below, but each shared vCPU is guaranteed only 6.25% of a core, with a small burst allowance to start, so a new one would not fit 20 CPU-seconds of work into a minute. The performance class is the fair comparison for agent work.

The price gap buys less than it seems. Daytona gives you an agent sandbox: SDKs, sessions, files, git and a code interpreter, a default idle stop after 15 minutes, and GPU or Windows machines when you need them. A Machine is a VM you drive yourself through the Machines API, with a temporary root disk and volumes for anything that must last.

Container or microVM?

A Daytona sandbox is a container unless you choose its VM class, and only VM sandboxes pause with memory and take memory snapshots. Every Fly Machine is a Firecracker microVM. So is every Runtime sandbox, with its own Linux kernel, and every one can pause with its memory and running processes. See microVM vs container and Firecracker vs Docker.

Cost for the same job

1,000 runs of a 2 vCPU, 4 GiB sandbox. Each run lasts 60 seconds and keeps the CPU busy for 20 CPU-seconds: an agent that mostly waits for a model. The Machine is a performance-2x with 4 GB.

TextDaytona   CPU    1,000 × 60 s / 3,600 × 2 × $0.0504 = $1.68          Memory 1,000 × 60 s / 3,600 × 4 × $0.0162 = $1.08          Total                                        $2.76Machines  Size   1,000 × 60 s / 3,600 × $0.0861     = $1.44Runtime   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 Daytona, $143.50 on Machines and $63.89 on Runtime. With both CPUs busy for the whole minute, it is $1.33 on Runtime against $2.76 on Daytona and $1.44 on Machines, so Runtime is cheaper however busy the sandbox is. If each run lasted 90 seconds instead, it would be $4.14 on Daytona, $2.15 on Machines and $0.89 on Runtime, since Runtime's CPU charge follows the 20 CPU-seconds of work rather than the clock. Disk, volumes, network and free credits are left out.

Which one to pick

• Pick Daytona for an agent sandbox with GPUs or Windows, sandboxes in the EU as well as the US, or $200 of free compute to start.
• Pick Fly Machines for general VMs in 18 regions with volumes and Managed Postgres in the same account, if you are building your own sandbox layer.
• Pick Runtime for a microVM on every sandbox at under half a Machine's price and under a quarter of Daytona's, pause that keeps memory, and an agent that connects without an API key.

Switch from either one

From Daytona, Runtime's SDK runs your code after one import change:

TypeScriptimport { Daytona } from "withruntime/daytona"; // was: from "@daytona/sdk"

Pythonfrom withruntime.daytona import Daytona  # was: from daytona import Daytona

Sandboxes get Daytona's defaults, 1 vCPU, 1 GiB and a 3 GiB disk, and pause after 15 minutes without calls, with their memory kept.

From Fly Machines, where you start a Machine for each job, create a sandbox instead and let with stop it when the job ends:

Pythonfrom withruntime import Sandboxwith Sandbox.create(funding="trial") as box:    print(box.exec("python3 -c 'print(6 * 7)'", check=True).stdout)

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 fly-machines (or --from daytona) prices what you ran at the old provider's rates. The full side-by-sides are Runtime vs Daytona and Runtime vs Fly.io.

Sources

Daytona and Fly.io pricing pages rechecked 25 September 2026; the rest checked 23 September 2026.

• Daytona pricing, Daytona sandboxes
• Fly.io pricing, Machine CPU performance, Fly Volumes, Fly.io regions
• Runtime pricing

Facts on this page were checked on 25 September 2026.