# Fly Sprites vs Freestyle: persistent computers for agents

Sprites and Freestyle VMs both persist between sessions. Sprites meter use; Freestyle bills allocation. The benchmark: $3.31 on Sprites, $2.25 on Freestyle.

**Runtime costs 81% less than Sprites and 72% less than Freestyle for an agent
that waits.** 1,000 runs of a minute on 2 vCPU and 4 GiB, 20 CPU-seconds
each: $3.31 on Fly Sprites, $2.25 on Freestyle, $0.64 on Runtime.

## At a glance

|           | Fly Sprites                           | Freestyle                         | Runtime                                                  |
| --------- | ------------------------------------- | --------------------------------- | -------------------------------------------------------- |
| Isolation | Firecracker microVM                   | Full Linux virtual machines       | Firecracker microVM, own kernel                          |
| CPU       | $0.07 per CPU-hour of measured CPU    | $0.04032 per allocated vCPU-hour  | $0.025 per vCPU-hour of measured CPU, with a small floor |
| Memory    | $0.04375 per GB-hour of memory in use | $0.0129 per GiB-hour              | $0.0075 per reserved GiB-hour                            |
| Asleep    | Disk at $0.02 per GB-month            | Storage at $0.000086 per GiB-hour | $0.08 per GB-month, memory included                      |
| SDKs      | JavaScript, Python, Go, Elixir        | TypeScript                        | JavaScript and Python, CLI and MCP                       |

## Where the money goes

Sprites charge little for CPU because they measure it, but their memory rate
is more than three times Freestyle's, and memory is most of this job. Freestyle
bills its lower rates on everything allocated, idle or not. Runtime pairs
measured CPU with the lowest memory rate of the three.

## Cost for the same job

The benchmark, 60 seconds a run, with 4 GB in use on Sprites and a 32 GiB
disk on Freestyle:

```
Sprites    CPU    1,000 × 20 s / 3,600 × $0.07                  = $0.39
           Memory 1,000 × 60 s / 3,600 × 4 × $0.04375           = $2.92
           Total                                                  $3.31

Freestyle  CPU    1,000 × 60 s / 3,600 × 2 × $0.04032           = $1.34
           Memory 1,000 × 60 s / 3,600 × 4 × $0.0129            = $0.86
           Disk   1,000 × 60 s / 3,600 × 32 × $0.000086         = $0.05
           Total                                                  $2.25

Runtime    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
```

Were both CPUs busy for the whole minute, the job would cost $5.25 on Sprites, $2.25 on Freestyle and $1.33 on Runtime.

## Which one to pick

- **Fly Sprites** for a personal machine with a 100 GB disk that sleeps
  cheaply.
- **Freestyle** for agent VMs with live forks, up to 32 vCPUs on Pro.
- **Runtime** for the lowest bill busy or waiting, and a Python SDK as well
  as JavaScript.

See [Runtime vs Fly.io](/docs/fly-alternative) and
[Runtime vs Freestyle](/docs/freestyle-alternative).

## Sources

Fly Sprites rates checked 23 September 2026; Freestyle rates checked 25 September 2026.

- [Fly.io pricing](https://fly.io/pricing/), [Sprites](https://fly.io/sprites/)
- [Freestyle pricing](https://www.freestyle.sh/pricing), [Freestyle VM pricing and limits](https://www.freestyle.sh/docs/vms/pricing-and-limits)
- Runtime [pricing](/docs/pricing)

Facts on this page were checked on 25 September 2026.