# Cloudflare Sandbox vs Prime Sandboxes: pricing and fit

Cloudflare bills active CPU but needs 3 GiB per vCPU; Prime bills everything while running. The 2 vCPU benchmark is $1.35 on Cloudflare and $1.52 on Prime.

**Runtime costs 53% less than Cloudflare and 58% less than Prime on it.**
1,000 one-minute runs of a 2 vCPU, 4 GiB sandbox with 20 CPU-seconds of work
each: $1.35 on Cloudflare Sandbox (priced at its 6 GiB minimum), $1.52 on
Prime Sandboxes and $0.64 on Runtime.

## At a glance

|           | Cloudflare Sandbox                                       | Prime Sandboxes                                | Runtime                                                  |
| --------- | -------------------------------------------------------- | ---------------------------------------------- | -------------------------------------------------------- |
| Isolation | A container in its own VM                                | Hardware-virtualized microVM, own guest kernel | Firecracker microVM, own kernel                          |
| CPU       | $0.072 per active vCPU-hour                              | $0.02 per vCPU-hour while running              | $0.025 per vCPU-hour of measured CPU, with a small floor |
| Memory    | $0.009 per provisioned GiB-hour, 3 GiB per vCPU at least | $0.0125 per GiB-hour                           | $0.0075 per reserved GiB-hour                            |
| Largest   | 4 vCPUs, 12 GiB, 20 GB                                   | 16 vCPUs, 64 GiB, 128 GiB of disk              | 16 vCPUs and 64 GiB, paid                                |
| Idle      | Sleeps after 10 idle minutes; files lost                 | Idle timeout off by default                    | Pause keeps memory, 1 to 365 days                        |
| Fleet     | 1,500 vCPUs per account                                  | 1,024 sandboxes, 4,096 vCPUs to start          | 100 sandboxes (50 the first week), 200 vCPUs             |

## Edge against scale

Cloudflare places a sandbox near the user who asked for it and bills only the
CPU that works, but forces memory up with CPU and forgets files on sleep.
Prime runs large microVMs by the thousand at a flat low rate. Both suit short
tasks; neither keeps a sandbox's memory between steps today.

## Cost for the same job

The benchmark, 60 seconds a run (6 GiB and a 12 GB disk on Cloudflare, 5 GiB
of disk on Prime):

```
Cloudflare  CPU    1,000 × 20 s × $0.000020                     = $0.40
            Memory 1,000 × 60 s × 6 × $0.0000025                = $0.90
            Disk   1,000 × 60 s × 12 × $0.00000007              = $0.05
            Total                                                  $1.35

Prime       CPU    1,000 × 60 s / 3,600 × 2 × $0.02              = $0.67
            Memory 1,000 × 60 s / 3,600 × 4 × $0.0125            = $0.83
            Disk   1,000 × 60 s / 3,600 × 5 × $0.0002            = $0.02
            Total                                                  $1.52

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
```

With both CPUs busy for the whole minute, the job costs $3.35 on Cloudflare, $1.52 on Prime and $1.33 on Runtime.

## Which one to pick

- **Cloudflare Sandbox** for Workers apps that want sandboxes at the edge.
- **Prime Sandboxes** for large, parallel RL rollouts.
- **Runtime** for the lowest cost and memory kept across pauses.

See [Runtime vs Cloudflare Sandbox](/docs/cloudflare-sandbox-alternative) and
[Runtime vs Prime Sandboxes](/docs/prime-sandboxes-alternative).

## Sources

Cloudflare rates checked 23 September 2026; Prime Sandboxes rates checked 25 September 2026.

- [Cloudflare Containers pricing](https://developers.cloudflare.com/containers/pricing/), [Containers limits and instance types](https://developers.cloudflare.com/containers/platform/limits/)
- [Prime Sandboxes overview](https://docs.primeintellect.ai/sandboxes/overview), [Prime Sandboxes launch](https://www.primeintellect.ai/blog/sandboxes)
- Runtime [pricing](/docs/pricing)

Facts on this page were checked on 25 September 2026.