# Presidio vs OpenAI Guardrails

> OpenAI Guardrails scores 69.5 (B) on agent readiness against Presidio's 66 (B), and leads in 4 of 7 scored categories. Presidio leads on reliability. Both do guard pii. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/microsoft-presidio-vs-openai-guardrails
- Markdown: https://www.anchorterminal.com/compare/microsoft-presidio-vs-openai-guardrails.md (~2,450 tokens)
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- Updated: 2026-10-09

OpenAI Guardrails scores 69.5 (B) on agent readiness against Presidio's 66 (B), and leads in 4 of 7 scored categories. Presidio leads on reliability. Both do guard pii.

- Presidio: grade B, 66/100, rank #281 of 842. Markdown https://www.anchorterminal.com/tools/microsoft-presidio.md · JSON https://www.anchorterminal.com/api/v1/tools/microsoft-presidio.json
- OpenAI Guardrails: grade B, 69.5/100, rank #175 of 842. Markdown https://www.anchorterminal.com/tools/openai-guardrails.md · JSON https://www.anchorterminal.com/api/v1/tools/openai-guardrails.json

## Which one, for what

### Presidio (B)

Good for: Detecting and masking personal data in prompts, outputs, logs and images on the owner's own machines, with detection tuned by entity, threshold and custom recognisers.

Ahead on:
- Reliability, 78 against 73

Also in its favour:
- No key needed to call it

Watch for: The REST containers have no authentication by design. The FAQ says to put a gateway or proxy in front

### OpenAI Guardrails (B)

Good for: Teams already on the OpenAI client or Agents SDK that want several checks from one config file with little code.

Ahead on:
- Security & auth, 59 against 53
- Maintenance & community, 89 against 63
- Transparency & trust, 76 against 65

Watch for: By default a check that fails to run returns `tripwire_triggered=False`, so the request continues. Strict mode is opt-in


## Score by category

| Category | Weight | Presidio | OpenAI Guardrails | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 78 | 73 | Presidio +5 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 69 | 66 | Presidio +3 |
| Agent ergonomics | 13% (16.2 this run) | 69 | 73 | OpenAI Guardrails +4 |
| Security & auth | 14% (17.5 this run) | 53 | 59 | OpenAI Guardrails +6 |
| 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) | 63 | 89 | OpenAI Guardrails +26 |
| Transparency & trust | 7% (8.8 this run) | 65 | 76 | OpenAI Guardrails +11 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **66 · B** | **69.5 · B** | |

## Facts side by side

| Fact | Presidio | OpenAI Guardrails |
| --- | --- | --- |
| Kind | SDK + MCP | Agent framework |
| Vendor | Data Privacy Stack | OpenAI |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP | HTTP |
| Auth | None | API key |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | MIT | MIT |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-07-22 | 2026-09-10 |
| Terms last updated | no document linked | no document linked |
| Privacy policy last updated | no document linked | 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 | 11k stars, 1.2M PyPI/wk | 259 stars, 19k npm/wk, 105k PyPI/wk |

## Verdicts

**Presidio.** MIT-licensed personal data detector with a public OpenAPI document, tests on Python 3.10 to 3.14 and about 1.2 million weekly PyPI downloads. The REST containers have no authentication, the project states no SLA or support, and it covers personal data only, with no prompt injection or content moderation checks.

**OpenAI Guardrails.** MIT-licensed wrapper that adds twelve configurable checks to OpenAI client calls from one JSON file, with tool-level injection checks for the Agents SDK. The README labels it a preview at version 0.3.3, and by default a check that fails to run is reported as passed unless `raise_guardrail_errors=True` is set.

## Before you call either

### Presidio

1. Install from PyPI or pull images from ghcr.io/data-privacy-stack. The mcr.microsoft.com/presidio-* images are no longer updated
2. Download a spaCy model (python -m spacy download en_core_web_lg) before the first `AnalyzerEngine()` call, or use the Docker image
3. Send both text and language to `/analyze`. A request missing either returns HTTP 500 with a JSON error field
4. Pass entities and score_threshold to limit results. Many country-specific recognisers are disabled by default and need enabling in the registry YAML
5. Keep the containers on a private network or behind your own authenticating proxy. They accept any caller

### OpenAI Guardrails

1. Pass `raise_guardrail_errors=True` to the client. The default treats a check that failed to run as passed
2. Run `python -m spacy download en_core_web_sm` before using Contains PII, or client initialisation fails
3. Catch `GuardrailTripwireTriggered`, and append a user message to history only after the call returns without it
4. Use `block=true` for Contains PII in the output stage. Masking works only in the pre-flight stage
5. Keep `stream=False` where output must be checked before it is shown, and budget one extra model call per LLM-based check

## Questions

### Which is better for AI agents, Presidio or OpenAI Guardrails?

OpenAI Guardrails scores 69.5 (B) on agent readiness against Presidio's 66 (B), and leads in 4 of 7 scored categories. Presidio leads on reliability.

### Are Presidio and OpenAI Guardrails open source?

Yes. Presidio is open source (MIT). OpenAI Guardrails is open source (MIT).


## For agents

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

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