# Free sandbox APIs for AI agents (2026)

> What each hosted sandbox API gives an AI agent for free (Prized, E2B, Daytona, Modal, Vercel Sandbox, Freestyle, CodeSandbox, Sprites, Blaxel and Tensorlake), with the limits that come with it, the open-source ones you can host, and a Prized sandbox started in one call, each fact from the vendor's own pages, checked October 31, 2026.

URL: https://prized.dev/docs/free-sandbox-api
Updated: 2026-10-31

Hosted sandbox APIs give free use in three forms: credit (Prized, E2B, Daytona, Sprites, Blaxel), an allowance that comes back every month (Modal, Vercel Sandbox, Freestyle, CodeSandbox), or a free plan with fixed limits (Tensorlake). What it buys differs more than the dollar figure: how long a sandbox may run, how many run at once, how big each is, and whether you need a card.

## Free use at a glance [#free-use-at-a-glance]

|  | Free use | Card needed | Run length on it | At once | Largest sandbox on it |
| --- | --- | --- | --- | --- | --- |
| Prized | $30 of credit once | No | 60 minutes of running in all per sandbox; paused time does not count | 10 sandboxes, 20 vCPU and 40 GB in all | 2 vCPU, 4 GB |
| E2B | $100 of credit once | No | 1 hour at a time; a pause resets it | 20 | 8 vCPU, 8 GB |
| Daytona | $200 of compute | No | No limit; stops after 15 idle minutes by default | 10 vCPU in all on Tier 1 | 4 vCPU, 8 GB |
| Modal | $30 of credit a month on Starter | A payment method on file | 24 hours; 5 minutes by default | 100 containers | No number listed |
| Vercel Sandbox | 5 CPU-hours, 420 GB-hours of memory and 5,000 creations a month on Hobby | Not stated | 45 minutes a session; a stop and resume resets it | 10 | 4 vCPU, 8 GB |
| Freestyle | 200 vCPU-hours and 400 GB-hours of memory a month | Not stated | No limit listed | 10 VMs | 4 vCPU, 8 GB |
| CodeSandbox SDK | 400 credits a month, about 40 hours of its Nano VM (2 cores, 4 GB) | Not stated | No limit | 10 VMs | 4 vCPU, 8 GB |
| Sprites, from Fly.io | $30 of trial credit once | Not stated | No limit listed; sleeps when idle | Not stated | 8 vCPU, memory managed for you |
| Blaxel | Up to $200 of credit | Not stated | A sandbox expires within 7 days on Tier 0 | 10 on Tier 0 | Not listed |
| Tensorlake | A free plan with no usage charge | Not stated | 2 hours a session | 1 | 1 vCPU, 1 GB |

"Not stated" means the vendor's pages don't say. Past a monthly allowance, Vercel pauses sandbox creation and Freestyle pauses VMs until it resets; past a one-time credit, you top up or start a plan. Cloudflare Sandboxes have no free use: they need the Workers Paid plan, $5 a month. Together Code Sandbox is turned on through its sales team.

## Prized's free tier, exactly [#prizeds-free-tier-exactly]

* **$30 of credit, once per person, no card.** It does not refill, and sandboxes draw on it at $0.04 per vCPU-hour, $0.0125 per GB-hour of memory and $0.0001 per GB-hour of disk: a 2 vCPU, 4 GB sandbox is $0.131 an hour. The $30 of free credit covers about 2,700 five minute sandboxes of 2 vCPU and 4 GB.
* **Limits while the balance is free credit alone:** 10 sandboxes at once, 20 vCPU and 40 GB running across the workspace, each up to 2 vCPU and 4 GB, 60 minutes of running in all per sandbox, and 100 GB of disk across the workspace's sandboxes ([Free tier](https://prized.dev/docs/sandboxes#free-tier)).
* **Paused sandboxes** keep their memory and disk, on the machine they ran on, until 30 days after their last use, then are deleted ([Paused retention](https://prized.dev/docs/sandboxes#paused-retention)).
* **Included:** pause with memory, fork into live copies (the copies keep the parent's deletion time), outbound internet, and both templates: `prized-base-v1` (Ubuntu with Python 3, Node.js 22 and git) and `prized-agent-v1`, which adds Claude Code and Codex.
* **The free credit's rules hold:** one process at full CPU for 30 minutes can pause the workspace's sandboxes ([Free credit](https://prized.dev/docs/billing#free-credit)).
* **To lift it:** a [top-up](https://prized.dev/docs/billing#topping-up) from $10 or a plan lifts a workspace to the full [quotas](https://prized.dev/docs/limits#sandboxes): 24 hours of running by default, up to 7 days, and up to 32 vCPU and 128 GB a sandbox.
* **An account a coding agent makes** with your email through [agent sign-in](https://prized.dev/docs/agent-sign-in) can get the credit, once per inbox, if the sign-up passes Prized's checks ([Boxes and billing](https://prized.dev/docs/agent-sign-in#boxes-and-billing)).

Sandboxes have no GPUs. Not yet: your own image, Docker, root, and regions other than Oregon ([Not yet](https://prized.dev/docs/sandboxes#not-yet)).

## Start a sandbox in one call [#start-a-sandbox-in-one-call]

1. **Get a key:** [Open Sandboxes](https://prized.dev/onboarding/sandboxes) signs you up with the $30 of free credit and no card; click **Create API key** and export it as `PRIZED_API_KEY`. A coding agent can make the account and its key with your email address instead ([Agent quickstart](https://prized.dev/docs/sandboxes-agent-quickstart)).
2. **Create a 2 vCPU, 4 GB sandbox** with `curl` and `jq`. The call holds its answer up to 8 seconds while the sandbox starts and keeps its address in `TOOLBOX`; a command sent while it is still starting waits up to 10 seconds for it. It deletes itself after 60 minutes of running:

```bash
TOOLBOX=$(curl -s -X POST "https://api.prized.dev/api/v1/sandboxes?wait=running" -H @<(echo "Authorization: Bearer $PRIZED_API_KEY") -H "Content-Type: application/json" -d '{"template":"prized-base-v1","resources":{"vcpu":2,"memoryMb":4096},"maxRuntimeMin":60}' | jq -er '.sandbox.toolboxBase // error(tojson)')
```

3. **Run a command in it:**

```bash
curl -s -X POST "$TOOLBOX/process/execute" -H @<(echo "Authorization: Bearer $PRIZED_API_KEY") -H "Content-Type: application/json" -d '{"command":"python3 --version"}'
# {"stdout":"Python 3.12.3\n","stderr":"","exitCode":0,"durationMs":41}
```

A refused create prints its error instead, with the free-tier limit it hit ([Free tier](https://prized.dev/docs/sandboxes#free-tier)). Files, background processes, pause, fork and delete are one call each ([Sandbox API](https://prized.dev/docs/sandboxes-api)).

## Host one yourself [#host-one-yourself]

Open-source sandboxes cost what the machines under them cost, and you run them yourself:

* **[E2B's runtime](https://github.com/e2b-dev/runtime)** (Apache-2.0): the stack behind E2B's cloud, for your own machines.
* **[OpenSandbox](https://github.com/opensandbox-group/OpenSandbox)** (Apache-2.0), formerly at alibaba/OpenSandbox.
* **[microsandbox](https://github.com/superradcompany/microsandbox)** (Apache-2.0): a microVM runtime and library that runs locally.
* **[Agent Sandbox](https://github.com/kubernetes-sigs/agent-sandbox)** (Apache-2.0): isolated, stateful workloads on your Kubernetes cluster.
* **[Daytona](https://github.com/daytonaio/daytona)** (AGPL-3.0): free to use and fork, but no longer maintained; Daytona moved its core development to a private codebase in June 2026.

## Common questions [#common-questions]

### Which sandbox API is free without a credit card? [#which-sandbox-api-is-free-without-a-credit-card]

Prized, E2B and Daytona say so on their own pages: $30, $100 and $200 of credit. Modal asks for a payment method on file before its $30 a month applies.

### Which free tier runs a sandbox longest? [#which-free-tier-runs-a-sandbox-longest]

Daytona and CodeSandbox set no run time limit, and Freestyle and Sprites list none, though Daytona stops a sandbox after 15 minutes with no toolbox calls, SSH or preview traffic unless you turn auto-stop off, and CodeSandbox hibernates one after the idle timeout you set, up to 24 hours. Modal allows 24 hours, Tensorlake 2 hours, E2B 1 hour at a time and Vercel 45 minutes a session. Prized's free tier gives each sandbox 60 minutes of running in all, and a top-up from $10 lifts it to 24 hours by default and up to 7 days.

### Is there a free sandbox API that keeps memory through a pause? [#is-there-a-free-sandbox-api-that-keeps-memory-through-a-pause]

Prized and E2B keep a paused sandbox's memory on their free use, Blaxel's standby and CodeSandbox's hibernation save it too, and a Sprite keeps it while it sleeps warm. Daytona does it on its Linux VM and Windows sandboxes, not its default containers. On the free tier a paused Prized sandbox is kept, on the machine it ran on, until 30 days after its last use; E2B keeps paused sandboxes with no time limit.

### Which free sandbox API fits a coding agent? [#which-free-sandbox-api-fits-a-coding-agent]

One with outbound internet, a run long enough for its task, and a way to keep its state between turns. On Prized, the `prized-agent-v1` template has Claude Code and Codex installed, and the [Prized skill](https://prized.dev/docs/sandboxes-coding-agents) teaches your coding agent the calls.

## Sources [#sources]

Checked October 31, 2026:

* **E2B:** [pricing](https://e2b.dev/pricing) (Hobby credit, card, sessions, concurrency), [billing](https://docs.e2b.dev/billing) (sizes, paused retention).
* **Daytona:** [pricing](https://www.daytona.io/pricing) (free compute, card), [limits](https://www.daytona.io/docs/en/limits) (tiers), [sandboxes](https://www.daytona.io/docs/en/sandboxes) (sizes, auto-stop, pause), [repository](https://github.com/daytonaio/daytona) (no longer maintained).
* **Modal:** [pricing](https://modal.com/pricing) (Starter credit), [billing](https://modal.com/docs/guide/billing) (payment method), [sandboxes](https://modal.com/docs/guide/sandboxes) (timeouts).
* **Vercel Sandbox:** [pricing and limits](https://vercel.com/docs/sandbox/pricing) (Hobby allowance, sessions, concurrency, sizes).
* **Freestyle:** [pricing and limits](https://www.freestyle.sh/docs/vms/pricing-and-limits) (free allowance, concurrency, sizes), [VM lifecycle](https://www.freestyle.sh/docs/vms/lifecycle) (pause keeps memory).
* **CodeSandbox SDK:** [pricing](https://codesandbox.io/pricing), [credits](https://codesandbox.io/docs/learn/credit-usage/credits) (400 a month on the free plan), [SDK pricing](https://codesandbox.io/docs/sdk/pricing) (concurrency, VM sizes), [hibernation](https://codesandbox.io/docs/sdk/hibernate) (memory and disk), [create](https://codesandbox.io/docs/sdk/create) (hibernation timeout).
* **Sprites:** [Sprites](https://fly.io/sprites) (trial credit), [lifecycle](https://docs.fly.io/sprites/concepts/lifecycle) (size, warm and cold sleep).
* **Blaxel:** [pricing](https://blaxel.ai/pricing) (free credit, Tier 0 sandboxes, standby keeps memory), [expiration](https://docs.blaxel.ai/Sandboxes/Expiration) (Tier 0 expiry).
* **Tensorlake:** [pricing](https://www.tensorlake.ai/pricing) (free plan), [billing](https://docs.tensorlake.ai/platform/billing) (limits).
* **Cloudflare Sandboxes:** [Containers pricing](https://developers.cloudflare.com/containers/platform/pricing/) (Workers Paid).
* **Together Code Sandbox:** [docs](https://docs.together.ai/docs/together-code-sandbox) (access through sales).
* **Open source:** each project's GitHub repository (license, latest release).

Something here out of date? Write to the support address shown on https://prized.dev/docs/troubleshooting.