Runtime costs 74% less than CodeSandbox for an agent that waits on a model, and more for short runs. 100,000 one-minute runs of a 2 vCPU, 4 GiB sandbox, each using 20 CPU-seconds, cost $63.89 a month on Runtime and $247.67 on CodeSandbox. Runtime bills by the second and charges for the CPU your code uses. Rates checked 25 October 2026.
How CodeSandbox bills
The CodeSandbox SDK sells VMs in fixed sizes, priced in credits per hour. The smallest, Nano, has 2 cores and 4 GB of memory. Each VM's running time is rounded up to the next whole minute.
| Nano VM | As published | Converted |
|---|---|---|
| Rate | 10 credits an hour | 10 × $0.01486 = $0.1486 an hour |
| Billing unit | By the minute, rounded up | A 40-second run is billed as a minute |
| Per minute | 1/60 of the hourly rate | About $0.00248 |
Runtime charges $0.025 per vCPU-hour of measured CPU, with a floor of a twentieth of a vCPU, and $0.0075 per reserved GiB-hour, billed by the second. The same shape costs $0.03125 an hour while it waits and $0.08 fully busy.
Because CodeSandbox sells fixed sizes, the calculator prices it only at 2 vCPUs and 4 GiB. Choose another shape and it lists CodeSandbox as unpriced.
Example workloads
A month of each at 2 vCPUs and 4 GiB, from the calculator above, with CodeSandbox's rounding applied.
| Workload | Runtime | CodeSandbox |
|---|---|---|
| Agent runs: 2 vCPU, 4 GiB, 60 s, 20 CPU-seconds, 100,000 a month | $63.89 | $247.67 |
| Every CPU busy: 2 vCPU, 4 GiB, 60 s, 120 CPU-seconds, 100,000 | $133.33 | $247.67 |
| Short runs: 2 vCPU, 4 GiB, 40 s, 24 CPU-seconds, 200,000 | $100.00 | $495.33 |
| Quick checks: 2 vCPU, 4 GiB, 20 s, 20 CPU-seconds, 500,000 | $152.78 | $1,238.33 |
The last two rows show the rounding. A 20-second check is billed as a full minute on CodeSandbox, three times its length, so Runtime saves 88% there. On whole-minute runs with both CPUs busy, Runtime still saves 46%.
Per run, that 20-second check costs $0.000306 on Runtime and $0.00248 on CodeSandbox. Runtime has no one-minute minimum, so short runs cost what they use.
CodeSandbox VMs keep memory in snapshots. A Runtime sandbox does too: a pause keeps its files, memory and running processes, and a fork copies a running sandbox, 1 to 100 copies at a time.
What the calculator leaves out
- Plan fees and concurrency. The free Build plan runs up to 10 VMs at the same time; more needs the Scale plan at $170 a month, which runs 250. Runtime has no plan: a paid account runs 100 sandboxes at the same time on prepaid credit from $10.
- Free start. CodeSandbox's is the free Build plan. Runtime's is 100 free hours of a 1 GB machine in the first 30 days, no card.
- Storage. Left out on both sides. A paused Runtime sandbox keeps its files, memory and running processes for $0.08 per GB a month.
Network and taxes are also left out.
Price your own runs exactly
With some runs on Runtime, price exactly those sandboxes as Nano VMs:
Terminalruntime compare --from codesandboxIt reads up to 90 days of settled sandboxes and prints what you save a month.
The rest of the comparison, snapshots and VM sizes included, is on Runtime vs CodeSandbox. The sandbox cost calculator prices the other providers for any shape, and pricing works through Runtime's cost per 1,000 runs.
Sources
The rates are from Together's documentation of the CodeSandbox SDK; CodeSandbox is a Together company.
- Together: CodeSandbox SDK, checked 25 October 2026
- CodeSandbox SDK pricing
- Runtime pricing
Rival rates on this page were checked on 25 October 2026.