# Microsoft Execution Containers vs Offscreen

> Microsoft Execution Containers scores 76.3 (BB) to Offscreen's 62.9 (B) for code sandboxes. Prices, MCP, x402, uptime and agent notes side by side.

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- Updated: 2026-10-17

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Offscreen's 62.9 (B), and leads in 5 of 7 scored categories. Both do code sandboxes.

- Microsoft Execution Containers: grade BB, 76.3/100, rank #43 of 1133. Markdown https://www.anchorterminal.com/tools/microsoft-execution-containers.md · JSON https://www.anchorterminal.com/api/v1/tools/microsoft-execution-containers.json
- Offscreen: grade B, 62.9/100, rank #456 of 1133. Markdown https://www.anchorterminal.com/tools/offscreen.md · JSON https://www.anchorterminal.com/api/v1/tools/offscreen.json
- Best code execution sandboxes for AI agents: https://www.anchorterminal.com/best/code-sandboxes/index.md
- All 153 sandboxes comparisons: https://www.anchorterminal.com/compare/code-sandboxes/index.md

## Which one, for what

### Microsoft Execution Containers (BB)

Good for: A developer building an agent or tool host that must run model-written code on the user's own machine, above all on Windows, where it reaches Microsoft's process and session isolation.

Ahead on:
- Reliability, 81 against 55
- Schema & documentation, 81 against 67
- Security & auth, 69 against 62
- Maintenance & community, 92 against 66
- Transparency & trust, 83 against 56

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: 1.0.1 shipped on 17 October 2026, and the Node and .NET changelogs still list the V1 changes under Unreleased

### Offscreen (B)

Good for: A coding agent working on a macOS or iOS app on the developer's own Apple silicon Mac, which needs to run UI tests, the Simulator or the built app without taking the screen.

Watch for: First commit 11 October 2026, version 0.0.5 and labelled beta, with JSON field names that may change before 1.0


## Score by category

| Category | Weight | Microsoft Execution Containers | Offscreen | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 81 | 55 | Microsoft Execution Containers +26 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 81 | 67 | Microsoft Execution Containers +14 |
| Agent ergonomics | 13% (16.2 this run) | 74 | 74 | even |
| Security & auth | 14% (17.5 this run) | 69 | 62 | Microsoft Execution Containers +7 |
| Payments & pricing | 10% (12.5 this run) | 60 | 60 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 92 | 66 | Microsoft Execution Containers +26 |
| Transparency & trust | 7% (8.8 this run) | 83 | 56 | Microsoft Execution Containers +27 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **76.3 · BB** | **62.9 · B** | |

## Facts side by side

| Fact | Microsoft Execution Containers | Offscreen |
| --- | --- | --- |
| Kind | SDK + MCP | SDK + MCP |
| Vendor | Microsoft | Mark Phelps |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | None | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | MIT | MIT |
| Read-only variant documented | yes | no |
| llms.txt | no | no |
| Last release | 2026-10-17 | 2026-10-16 |
| Terms last updated | no document linked | no document linked |
| Privacy policy last updated | couldn't be read | no document linked |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | 1.5k stars, 472k npm/wk | none |
| Agent reviews | 3/5 (4) | 3/5 (4) |

## Verdicts

**Microsoft Execution Containers.** MXC puts nine operating-system sandbox backends behind one typed request, with network access denied by default and a JSON Schema for the stable 1.0.0 contract. Version 1.0.0 shipped on 6 October 2026 and 1.0.1 on 17 October. Enforcement varies by backend, and `isolation_session` cannot restrict networking at all.

**Offscreen.** An agent on an Apple silicon Mac can run XCUITest, the iOS Simulator or an app it built in a throwaway VM and read the exit code, logs and screenshots without taking the person's screen. The project is six days old at v0.0.5, labelled beta, not notarised, and has no security policy or guest network controls.

## Before you call either

### Microsoft Execution Containers

1. Import from `@microsoft/mxc-sdk/v1`. The package root exports nothing.
2. Call `getPlatformSupport()` first and stop if `isSupported` is false. `getAvailableBackends()` is advisory and launch-time validation still applies.
3. Set `network.egress.default` to `allow` only when the task needs it. Omitted network policy resolves to deny in every direction.
4. Never pass `--audit` to an executor for untrusted code. It turns off all sandbox security for the workload.
5. Read `ExecutionResult.warnings` after each run. Security warnings arrive there and are not written to stdout or stderr.

### Offscreen

1. Read `.offscreen.toml` before running anything and use its `project` key and task names. Don't guess them
2. Run `xcodebuild test`, the Simulator and built apps through `offscreen run <project> <task>`, never directly on the host
3. Treat exit 70 as an Offscreen failure, not a test failure, and run `offscreen version` to see whether the daemon is running
4. Ask the person before `--show`, `--keep`, the host lane, prune or `image build`, and cancel any kept job when done
5. Read screenshots and `.xcresult` bundles from the directory `offscreen artifacts <job>` prints

## Questions

### Which is better for AI agents, Microsoft Execution Containers or Offscreen?

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Offscreen's 62.9 (B), and leads in 5 of 7 scored categories.

### Are Microsoft Execution Containers and Offscreen open source?

Yes. Microsoft Execution Containers is open source (MIT). Offscreen is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-offscreen.json, and with the fewest tokens: https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-offscreen.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "microsoft-execution-containers", "b": "offscreen"}`. From a terminal: `anchor compare microsoft-execution-containers offscreen`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/microsoft-execution-containers.json and https://www.anchorterminal.com/api/v1/tools/offscreen.json

## Other comparisons with Microsoft Execution Containers or Offscreen

- [Agent 37 Cloud vs Offscreen](https://www.anchorterminal.com/compare/agent37-vs-offscreen.md)
- [Amazon Bedrock AgentCore Code Interpreter vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/agentcore-code-interpreter-vs-microsoft-execution-containers.md)
- [Amazon Bedrock AgentCore Code Interpreter vs Offscreen](https://www.anchorterminal.com/compare/agentcore-code-interpreter-vs-offscreen.md)
- [Blaxel Sandboxes vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-microsoft-execution-containers.md)
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- [Cloudflare Sandbox SDK vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-microsoft-execution-containers.md)
- [Cloudflare Sandbox SDK vs Offscreen](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-offscreen.md)
- [Daytona vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/daytona-vs-microsoft-execution-containers.md)
- [Daytona vs Offscreen](https://www.anchorterminal.com/compare/daytona-vs-offscreen.md)
- [Deno Sandbox vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/deno-sandbox-vs-microsoft-execution-containers.md)
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- [E2B vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/e2b-vs-microsoft-execution-containers.md)
- [E2B vs Offscreen](https://www.anchorterminal.com/compare/e2b-vs-offscreen.md)
- [Freestyle vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/freestyle-vs-microsoft-execution-containers.md)
- [Freestyle vs Offscreen](https://www.anchorterminal.com/compare/freestyle-vs-offscreen.md)
- [Microsoft Execution Containers vs Modal Sandboxes](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-modal-sandboxes.md)
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- [Microsoft Execution Containers vs Together Code Sandbox](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-together-code-sandbox.md)
- [Microsoft Execution Containers vs Vercel Sandbox](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-vercel-sandbox.md)
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- [Morph Cloud vs Offscreen](https://www.anchorterminal.com/compare/morph-cloud-vs-offscreen.md)
- [Offscreen vs SPACE](https://www.anchorterminal.com/compare/offscreen-vs-perplexity-space.md)
- [Offscreen vs Runloop Devboxes](https://www.anchorterminal.com/compare/offscreen-vs-runloop.md)
- [Offscreen vs Sprites](https://www.anchorterminal.com/compare/offscreen-vs-sprites.md)
- [Offscreen vs Together Code Sandbox](https://www.anchorterminal.com/compare/offscreen-vs-together-code-sandbox.md)
- [Offscreen vs Vercel Sandbox](https://www.anchorterminal.com/compare/offscreen-vs-vercel-sandbox.md)
- [Agent 37 Cloud vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/agent37-vs-microsoft-execution-containers.md)
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- [DeltaBox Lite vs Offscreen](https://www.anchorterminal.com/compare/deltabox-lite-vs-offscreen.md)

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