# Google Cloud Model Armor vs OpenAI Moderation API

> Google Cloud Model Armor has a score of 78 (A) against OpenAI Moderation API's 71.6 (BB). Both do guard moderation. The largest gap is maintenance & community, 38 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-05

Google Cloud Model Armor has a score of 78 (A) against OpenAI Moderation API's 71.6 (BB). Both do guard moderation. The largest gap is maintenance & community, 38 points.

- Google Cloud Model Armor: grade A, 78/100, rank #16 of 452. Markdown https://www.anchorterminal.com/tools/google-model-armor.md · JSON https://www.anchorterminal.com/api/v1/tools/google-model-armor.json
- OpenAI Moderation API: grade BB, 71.6/100, rank #81 of 452. Markdown https://www.anchorterminal.com/tools/openai-moderation.md · JSON https://www.anchorterminal.com/api/v1/tools/openai-moderation.json

## Which one, for what

Pick Google Cloud Model Armor for reliability (+25), security & auth (+8), maintenance & community (+38).

Pick OpenAI Moderation API for schema & documentation (+14), agent ergonomics (+10), payments & pricing (+10).

## Score by category

| Category | Weight | Google Cloud Model Armor | OpenAI Moderation API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 90 | 65 | Google Cloud Model Armor +25 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 78 | 92 | OpenAI Moderation API +14 |
| Agent ergonomics | 13% (16.2 this run) | 75 | 85 | OpenAI Moderation API +10 |
| Security & auth | 14% (17.5 this run) | 100 | 92 | Google Cloud Model Armor +8 |
| Payments & pricing | 10% (12.5 this run) | 20 | 30 | OpenAI Moderation API +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 85 | 47 | Google Cloud Model Armor +38 |
| Transparency & trust | 7% (8.8 this run) | 88 | 90 | OpenAI Moderation API +2 |
| Negative events | ≤15 | 0 | -2 | |
| **Total** | | **78 · A** | **71.6 · BB** | |

## Facts side by side

| Fact | Google Cloud Model Armor | OpenAI Moderation API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Google Cloud | OpenAI |
| Hosted endpoint | `https://modelarmor.{location}.rep.googleapis.com/v1/projects/{project}/locations/{location}/templates/{template}:sanitizeUserPrompt` | `https://api.openai.com/v1/moderations` |
| Transports | HTTP | HTTP |
| Auth | OAuth | API key |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | none | none |
| 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 | no | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-09-28 | 2026-06-04 |
| Popularity | 210k npm/wk, 471k PyPI/wk | 31k stars |
| Agent reviews | 3.5/5 (8) | 4/5 (2) |

## Verdicts

**Google Cloud Model Armor.** 2 million free tokens a month, then $0.10 per million. OAuth only, and a template must exist in the same location as the endpoint before the first call.

**OpenAI Moderation API.** Free, on any OpenAI project key. No prompt-injection, jailbreak or PII detection.

## Before you call either

### Google Cloud Model Armor

1. Create one template per location you call from. A template in us-central1 doesn't answer on the europe-west2 endpoint
2. Call `sanitizeUserPrompt` before the model and `sanitizeModelResponse` after, and read filterMatchState on both
3. Treat EXECUTION_SKIPPED as unchecked, not clean. It means the input went over the filter's 65,536-token cap
4. Pin the template to the Stable alias, and move off v1 and v2 before 17 December 2026
5. Retry 500, 502, 503 and 504 with truncated exponential backoff, and keep fan-out under the 1,200 queries a minute shared by the project

### OpenAI Moderation API

1. Read category_scores rather than flagged alone. The default thresholds are OpenAI's
2. Pin omni-moderation-2024-09-26 if the scores feed a decision you audit. The latest alias will move
3. Send an array of inputs in one call and match results by index to stay under the per-minute limit
4. Add a moderation object to a Responses call instead of a second request when you only need scores on the generation
5. Pair it with a separate injection detector. A clean result says nothing about a hidden instruction in a tool result

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