Fly Sprites vs AWS Lambda MicroVMs: persistent sandboxes and bursts

Sprites meter CPU used and memory in use; Lambda MicroVMs bill a baseline. On the 2 vCPU benchmark Sprites cost $3.31 and Lambda $4.20.

Runtime is 81% cheaper than Sprites and 85% cheaper than Lambda MicroVMs for an agent that waits. 1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox, 20 CPU-seconds apiece, cost $3.31 on Fly Sprites, $4.20 on AWS Lambda MicroVMs and $0.64 on Runtime.

At a glance

	Fly Sprites	AWS Lambda MicroVMs	Runtime
Isolation	Firecracker microVM	Firecracker microVM	Firecracker microVM, own kernel
CPU	$0.07 per CPU-hour of measured CPU	$0.0997 per baseline vCPU-hour	$0.025 per vCPU-hour of measured CPU, with a small floor
Memory	$0.04375 per GB-hour of memory in use	$0.0132 per GB-hour	$0.0075 per reserved GiB-hour
Disk	100 GB, kept always; $0.02 per GB-month asleep	In the snapshot, $0.08 per GB-month	Included while running; $0.08 per GB-month paused
Lifetime	Persistent; pauses itself	State kept up to 8 hours	Leases extended, persistent, pauses up to 365 days

Measured CPU, costly memory

Sprites and Runtime both charge CPU only while it works, which is why Sprites' CPU line here is 39 cents against Lambda's $3.32. Memory reverses it: at $0.04375 per GB-hour, Sprites' memory costs more than three times Lambda's. Runtime's measured CPU comes with memory at $0.0075 per GiB-hour.

Cost for the same job

The benchmark, 60 seconds a run, with 4 GB of memory in use on Sprites and a 4 GB baseline on Lambda:

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                                                  $3.31Lambda   CPU    1,000 × 60 s × 2 × $0.0000276944              = $3.32         Memory 1,000 × 60 s × 4 × $0.0000036667              = $0.88         Total                                                  $4.20Runtime  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

Kept busy for the whole minute on both CPUs, the job would be $5.25 on Sprites, $4.20 on Lambda and $1.33 on Runtime.

Which one to pick

• Fly Sprites for a personal, always-there computer with a large disk that sleeps for pennies.
• Lambda MicroVMs for bursts that must run inside AWS.
• Runtime for agents at the lowest bill, busy or idle, with memory kept across pauses.

See Runtime vs Fly.io and Runtime vs AWS Lambda MicroVMs.

Sources

Fly Sprites rates checked 23 September 2026; Lambda MicroVMs rates checked 25 September 2026.

• Fly.io pricing, Sprites
• AWS Lambda pricing, Lambda MicroVMs
• Runtime pricing

Facts on this page were checked on 25 September 2026.