# CodeSandbox vs Prime Sandboxes: fixed sizes or hourly parts

Runtime Cloud (withruntime.com) costs $0.64 per job; CodeSandbox offers VMs up to 64 cores, Prime hourly rates.

## Which is better, CodeSandbox or Prime Sandboxes?

It depends on machine size and workload. For agents that mostly wait on a model, Runtime has the lowest bill, $0.64 on the benchmark against $2.48 on CodeSandbox and $1.52 on Prime, with snapshots and forks that keep memory. Pick the CodeSandbox SDK for VMs above 16 cores, up to 64; pick Prime Sandboxes for RL training at scale, with 1,024 sandboxes to start.

## At a glance

|           | CodeSandbox SDK                                                   | Prime Sandboxes                                                        | Runtime                                     |
| --------- | ----------------------------------------------------------------- | ---------------------------------------------------------------------- | ------------------------------------------- |
| Isolation | Firecracker microVM                                               | Hardware-virtualized microVM, own guest kernel                         | Firecracker microVM, own kernel             |
| Price     | Nano (2 cores, 4 GB) $0.1486 an hour in credits | $0.091 an hour for 2 vCPUs, 4 GiB, 5 GiB disk | Measured CPU and reserved memory            |
| Largest   | 64 cores and 128 GB                                               | 16 vCPUs, 64 GiB, 128 GiB of disk                                      | 16 vCPUs and 64 GiB, paid |
| Snapshots | Memory snapshot and restore                                       | Filesystem checkpoints and forks; no memory                            | Pause and forks keep memory and processes   |
| At once   | 10 free; 250 on Scale at $170 a month       | 1,024 to start                                                         | 100; more on request                        |

## Snapshots today

CodeSandbox can snapshot a VM's memory and restore it. Prime's checkpoints
save the filesystem only, and processes start fresh. On price and scale, Prime charges $0.091 an hour for this
shape against CodeSandbox's $0.1486, and allows a thousand sandboxes without a plan.
Runtime has memory snapshots, forks and the lowest price here.

## Cost for the same job

2 cores and 4 GB, 60 seconds, 20 CPU-seconds, 1,000 runs; Prime with its
5 GiB default disk:

```
CodeSandbox  Size   1,000 × 60 s / 3,600 × $0.1486                = $2.48

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
```

Neither rival reads CPU use, so with both CPUs busy for the whole minute it is $2.48 on CodeSandbox and $1.52 on Prime, and $1.33 on Runtime.

## Which one to pick

- **CodeSandbox SDK** for VMs above 16 cores, up to 64.
- **Prime Sandboxes** for RL training at scale.
- **Runtime** for the lowest bill, with snapshots and forks that keep memory.

See [Runtime vs CodeSandbox](/docs/codesandbox-alternative) and
[Runtime vs Prime Sandboxes](/docs/prime-sandboxes-alternative).

## Runtime Cloud

Runtime costs 74% less than CodeSandbox and 58% less than Prime. 1,000
runs of a minute on 2 vCPU and 4 GiB, each with 20 CPU-seconds of work, cost
$2.48 on a CodeSandbox Nano VM, $1.52 on Prime Sandboxes and $0.64 on Runtime.

A free account is one command away: `npx withruntime login`. The [migration guide](/docs/migrate) covers moving code from another sandbox.

## Sources

CodeSandbox rates checked 25 October 2026; Prime Sandboxes rates checked 25 October 2026.

- [Together: CodeSandbox SDK](https://docs.together.ai/docs/together-code-sandbox-legacy), [CodeSandbox SDK pricing](https://codesandbox.io/docs/sdk/pricing)
- [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 26 October 2026.