Fly Sprites vs Morph: pricing, snapshots and limits

Sprites checkpoint a persistent VM's filesystem and bill measured use; Morph snapshots memory and disk and bills MCUs for a VM's size.

Runtime takes Morph's memory snapshots and Sprites' metered CPU and prices the result 81% below Sprites and 62% below Morph. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox cost $3.31 on Fly Sprites, $1.67 on Morph and $0.64 on Runtime. A Runtime snapshot or fork holds a running sandbox's memory, and its CPU rate is about a third of Sprites'. Rates checked 23 September 2026.

At a glance

	Fly Sprites	Morph	Runtime
Isolation	Firecracker microVM	Full virtual machines	Firecracker microVM, own kernel
CPU	$0.07 per CPU-hour of measured CPU	$0.05 per MCU-hour for the machine's size	$0.025 per vCPU-hour of measured CPU, with a small floor
Memory	$0.04375 per GB-hour of memory in use	Inside the MCU: 4 GB per MCU	$0.0075 per reserved GiB-hour
Snapshots	The filesystem, copy-on-write, in about a second	Memory and disk; branches to many replicas	Files, memory and running processes
Pause	Automatic; memory kept in a warm pause, dropped when cold	Devboxes scale to zero and keep their memory	Keeps files, memory and processes, 1 to 365 days
Plan fee	None required; optional monthly plans	Free with no credit; Developer $40 and Team $250 a month	None; prepaid credit from $10
Free start	$30 of trial credit	1,000 MCUs with the $40 Developer plan	50 sandbox hours, no card
At once	Not stated on the pricing page	8 devboxes free, 32 on Developer, 128 on Team	100 sandboxes on a paid account to start

Which one keeps a machine's state?

They save different things. A Sprite snapshot is of the filesystem: Fly says it takes about a second, is copy-on-write so it stores only what changed, and rolls the disk back to that point. Running processes are not in it. A paused Sprite keeps its memory only while the pause is warm; once it goes cold, memory is dropped and processes start fresh on the next wake, which takes 1 to 2 seconds. Open TCP connections do not survive either kind of pause.

A Morph snapshot holds the machine's memory and disk, and Infinibranch starts hundreds of parallel replicas from one running machine. Snapshot storage is billed in MCUs: one MCU covers 5 TB-hours of snapshot, and Morph's example keeps an 8 vCPU, 8 GB, 8 GB-disk machine for $0.12 a month.

Runtime keeps the whole machine in each case. A pause keeps files, memory and processes for the retention you set, a snapshot starts new sandboxes later, and a fork makes 1 to 10 running copies at once. See what a sandbox snapshot is and what a sandbox fork is.

Cost for the same job

Priced for 1,000 runs of 60 seconds on 2 vCPU and 4 GiB, each with 20 CPU-seconds of work. The Sprite is charged for all 4 GB throughout the minute. Morph counts 2 vCPUs and 4 GB as 2 MCUs an hour.

TextSprites  CPU    1,000 × 20 s / 3,600 × $0.07          = $0.39         Memory 1,000 × 60 s / 3,600 × 4 × $0.04375   = $2.92         Total                                           $3.31Morph    Size   1,000 × 60 s / 3,600 × 2 MCU × $0.05  = $1.67Runtime  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

That is $330.56 on Sprites, $166.67 on Morph and $63.89 on Runtime for 100,000 runs a month. If both CPUs are busy for the whole minute, it is $1.33 on Runtime, $5.25 on Sprites and $1.67 on Morph. Of the two rivals Morph is cheaper at both loads, because a Sprite's memory rate is high; at 1 GB in use a Sprite would pay $1.12. Plan fees, included credit, storage, network and free credit are excluded.

Which one to pick

You want	Best fit
One lasting computer with a 100 GB disk, cheap while asleep	Fly Sprites
Fast rollbacks of the filesystem	Fly Sprites
An agent that searches by branching into hundreds of replicas	Morph
Snapshots and forks with memory and processes, measured CPU	Runtime

Runtime also keeps a pause for as long as you set, 1 to 365 days, and has no plan fee.

Moving to Runtime

The pattern both rivals serve, set a machine up once and start from it later, looks like this on Runtime:

Pythonfrom withruntime import Runtimeruntime = Runtime()with runtime.sandboxes.create() as base:    base.exec("pip install --quiet requests")    snapshot = base.snapshot(name="with-requests", retention_days=7)    with runtime.sandboxes.create(snapshot=snapshot["id"]) as copy:        print(copy.exec("python3 -c 'import requests; print(requests.__version__)'").stdout)    runtime.snapshots.delete(snapshot["id"])

Sprites calls port directly: client.createSprite(name) to Sandbox.create(), sprite.execFile(cmd, args) to exec([cmd, ...args]). npx withruntime compare --from fly or --from morph reprices what you ran, and npx withruntime switch --from fly before the first top-up matches it with credit, up to $100. The migration guide's one instruction lets a coding agent handle the port on a branch and test it on the free trial. More: Runtime vs Fly.io, Runtime vs Morph.

Sources

Rates checked 23 September 2026; the Sprites, Sprites lifecycle and Morph pricing pages read 25 September 2026.

• Fly.io pricing, Sprites, Sprites lifecycle
• Morph Cloud pricing, Morph Devboxes, Morph snapshots
• Runtime pricing and Python SDK

Facts on this page were checked on 25 September 2026.