# Fly Sprites vs Freestyle: persistent computers for agents

Runtime Cloud (withruntime.com) costs 72% less than either. Sprites meter use, and Freestyle bills allocation.

## Which is better, Fly Sprites or Freestyle?

It depends on how much memory the job holds and how you fork it. If your agent mostly waits on model replies, Runtime is the cheapest here: $0.64 for 1,000 one-minute runs, against $2.40 on Sprites and $2.25 on Freestyle, because it pairs measured CPU with a lower memory rate. Pick Fly Sprites for a personal machine with a 100 GB disk that costs little while asleep. Pick Freestyle for VMs of up to 32 vCPUs on Pro, or for forks taken without a pause.

## At a glance

|           | Fly Sprites                                              | Freestyle                                       | Runtime                                                        |
| --------- | -------------------------------------------------------- | ----------------------------------------------- | -------------------------------------------------------------- |
| Isolation | Firecracker microVM                                      | Full Linux virtual machines                     | Firecracker microVM, own kernel                                |
| CPU       | $0.0385 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    | $0.021875 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 meter it, but their memory rate
is over half as much again as 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 × $0.0385                  = $0.21
           Memory 1,000 × 90 s / 3,600 × 4 × $0.021875           = $2.19
           Total                                                  $2.40

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
```

If both CPUs were busy for the whole minute, the job would cost $3.47 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 costs
  little while asleep.
- **Freestyle** for VMs of up to 32 vCPUs on Pro, or forks with no pause.
- **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).

## Runtime Cloud

Runtime costs 73% less than Sprites and 72% less than Freestyle for an agent
that waits. 1,000 one-minute runs on 2 vCPU and 4 GiB, with 20 CPU-seconds
each: $2.40 on Fly Sprites, $2.25 on Freestyle, $0.64 on Runtime.

A paused Runtime sandbox keeps its memory, and there is no plan fee. Run `npx withruntime login` to start free, and use the [migration guide](/docs/migrate) for code you already have.

## Sources

Fly.io prices checked 25 October 2026.

Fly Sprites rates checked 25 October 2026; Freestyle rates checked 25 October 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 26 October 2026.