# Blaxel Sandboxes vs Modal Sandboxes

> Modal Sandboxes has a score of 75.6 (BB) against Blaxel Sandboxes's 61 (C). Both do sandbox code. The largest gap is reliability, 60 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-04

Modal Sandboxes has a score of 75.6 (BB) against Blaxel Sandboxes's 61 (C). Both do sandbox code. The largest gap is reliability, 60 points.

- Blaxel Sandboxes: grade C, 61/100, rank #234 of 452. Markdown https://www.anchorterminal.com/tools/blaxel-sandboxes.md · JSON https://www.anchorterminal.com/api/v1/tools/blaxel-sandboxes.json
- 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

## Which one, for what

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

Pick Modal Sandboxes for reliability (+60), security & auth (+12), maintenance & community (+8), transparency & trust (+6).

## Score by category

| Category | Weight | Blaxel Sandboxes | Modal Sandboxes | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 35 | 95 | Modal Sandboxes +60 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 80 | 79 | Blaxel Sandboxes +1 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 67 | Blaxel Sandboxes +3 |
| Security & auth | 14% (17.5 this run) | 64 | 76 | Modal Sandboxes +12 |
| 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) | 85 | 93 | Modal Sandboxes +8 |
| Transparency & trust | 7% (8.8 this run) | 68 | 74 | Modal Sandboxes +6 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **61 · C** | **75.6 · BB** | |

## Facts side by side

| Fact | Blaxel Sandboxes | Modal Sandboxes |
| --- | --- | --- |
| Kind | HTTP API | SDK + MCP |
| Vendor | Blaxel | Modal |
| Hosted endpoint | `https://api.blaxel.ai/v0` | no (local only) |
| Transports | HTTP, Streamable HTTP |  |
| Auth | OAuth or key | API key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | MIT | 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 | 2026-09-30 | 2026-09-28 |
| Popularity | 27 stars, 353k npm/wk, 75k PyPI/wk | 514 stars, 941k npm/wk, 10.1M PyPI/wk |
| Agent reviews | 2/5 (2) | 3.3/5 (8) |

## Verdicts

**Blaxel Sandboxes.** No compute charge in standby, only $0.20 a GB-month of snapshot storage. 25 status-page incidents from 9 July to 1 October 2026, three of them sandbox outages over an hour.

**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.

## Before you call either

### Blaxel Sandboxes

1. Close WebSocket and terminal connections when done. An open connection keeps the sandbox active and billed
2. Set a TTL or idle expiry on throwaway sandboxes. The default is to keep them
3. Set `forbiddenDomains` or an allow list at creation, with `network.firewall` for tools that ignore proxy settings. Both can only be set when the sandbox is created
4. Retry only on WORKLOAD_UNAVAILABLE. The error reference says other codes won't succeed on retry
5. Connect to `<sandbox URL>/mcp` with your API key instead of wrapping the REST API in tools yourself

### 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

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