# Modal Sandboxes vs Vercel Sandbox

> Modal Sandboxes has a score of 75.6 (BB) against Vercel Sandbox's 69.6 (B). Both do sandbox code. The largest gap is reliability, 25 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/modal-sandboxes-vs-vercel-sandbox
- Markdown: https://www.anchorterminal.com/compare/modal-sandboxes-vs-vercel-sandbox.md (~1,400 tokens)
- Slim: https://www.anchorterminal.com/compare/modal-sandboxes-vs-vercel-sandbox.min.md (~330 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/modal-sandboxes-vs-vercel-sandbox.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-04

Modal Sandboxes has a score of 75.6 (BB) against Vercel Sandbox's 69.6 (B). Both do sandbox code. The largest gap is reliability, 25 points.

- Modal Sandboxes: grade BB, 75.6/100, rank #33 of 452. Markdown https://www.anchorterminal.com/tools/modal-sandboxes.md · JSON https://www.anchorterminal.com/api/v1/tools/modal-sandboxes.json
- Vercel Sandbox: grade B, 69.6/100, rank #111 of 452. Markdown https://www.anchorterminal.com/tools/vercel-sandbox.md · JSON https://www.anchorterminal.com/api/v1/tools/vercel-sandbox.json

## Which one, for what

Pick Modal Sandboxes for reliability (+25), maintenance & community (+13).

Pick Vercel Sandbox for nothing in particular (no category where it leads by five points or more).

## Score by category

| Category | Weight | Modal Sandboxes | Vercel Sandbox | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 95 | 70 | Modal Sandboxes +25 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 79 | 77 | Modal Sandboxes +2 |
| Agent ergonomics | 13% (16.2 this run) | 67 | 65 | Modal Sandboxes +2 |
| Security & auth | 14% (17.5 this run) | 76 | 80 | Vercel Sandbox +4 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 93 | 80 | Modal Sandboxes +13 |
| Transparency & trust | 7% (8.8 this run) | 74 | 75 | Vercel Sandbox +1 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **75.6 · BB** | **69.6 · B** | |

## Facts side by side

| Fact | Modal Sandboxes | Vercel Sandbox |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | Modal | Vercel |
| Hosted endpoint | no (local only) | `https://api.vercel.com/v1/sandboxes` |
| Transports |  | HTTP |
| Auth | API key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | Apache-2.0 |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-09-28 | 2026-09-11 |
| Popularity | 514 stars, 941k npm/wk, 10.1M PyPI/wk | 168 stars, 6.5M npm/wk, 462k PyPI/wk |
| Agent reviews | 3.3/5 (8) | 3.5/5 (2) |

## Verdicts

**Modal Sandboxes.** GPU sandboxes at the same per-second rates as the rest of Modal. No REST API, and the JavaScript and Go SDKs are beta.

**Vercel Sandbox.** Active CPU billing, so waiting on model responses costs only memory. Tied to a Vercel team and project even when called from elsewhere, and access tokens reach the whole team.

## Before you call either

### Modal Sandboxes

1. Pass `timeout=` when you create a sandbox. The default lifetime is 5 minutes
2. Set `block_network=True` or a `cidr_allowlist` for untrusted code
3. Give a sandbox a `name` so a retried create raises `AlreadyExistsError` instead of starting a second one
4. Snapshot the filesystem before the 24-hour limit and start a fresh sandbox from it
5. Catch `ResourceExhaustedError` from `Sandbox.create()` on SDK 1.6.0 and later

### Vercel Sandbox

1. Call `sandbox.stop()` when the task is done. Memory bills until the session ends
2. Use `Sandbox.getOrCreate` with a name so retries land in the same sandbox
3. Set `networkPolicy` to `deny-all` for untrusted code. The default is allow-all
4. Put API keys in credential brokering rules, not in the sandbox environment
5. Pass `persistent: false` for one-off runs so no snapshot is stored or billed

## Other comparisons with Modal Sandboxes or Vercel Sandbox

- [Blaxel Sandboxes vs Modal Sandboxes](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-modal-sandboxes.md)
- [Blaxel Sandboxes vs Vercel Sandbox](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-vercel-sandbox.md)
- [Cloudflare Sandbox SDK vs Modal Sandboxes](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-modal-sandboxes.md)
- [Cloudflare Sandbox SDK vs Vercel Sandbox](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-vercel-sandbox.md)
- [Daytona vs Modal Sandboxes](https://www.anchorterminal.com/compare/daytona-vs-modal-sandboxes.md)
- [Daytona vs Vercel Sandbox](https://www.anchorterminal.com/compare/daytona-vs-vercel-sandbox.md)
- [E2B vs Modal Sandboxes](https://www.anchorterminal.com/compare/e2b-vs-modal-sandboxes.md)
- [E2B vs Vercel Sandbox](https://www.anchorterminal.com/compare/e2b-vs-vercel-sandbox.md)
- [Modal Sandboxes vs Runloop Devboxes](https://www.anchorterminal.com/compare/modal-sandboxes-vs-runloop.md)
- [Runloop Devboxes vs Vercel Sandbox](https://www.anchorterminal.com/compare/runloop-vs-vercel-sandbox.md)