# Amazon Bedrock Guardrails vs Azure AI Content Safety (Prompt Shields)

> Amazon Bedrock Guardrails has a score of 75.1 (BB) against Azure AI Content Safety (Prompt Shields)'s 60.9 (C). Both do guard injection. The largest gap is reliability, 25 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-04

Amazon Bedrock Guardrails has a score of 75.1 (BB) against Azure AI Content Safety (Prompt Shields)'s 60.9 (C). Both do guard injection. The largest gap is reliability, 25 points.

- Amazon Bedrock Guardrails: grade BB, 75.1/100, rank #41 of 452. Markdown https://www.anchorterminal.com/tools/amazon-bedrock-guardrails.md · JSON https://www.anchorterminal.com/api/v1/tools/amazon-bedrock-guardrails.json
- Azure AI Content Safety (Prompt Shields): grade C, 60.9/100, rank #237 of 452. Markdown https://www.anchorterminal.com/tools/azure-ai-content-safety.md · JSON https://www.anchorterminal.com/api/v1/tools/azure-ai-content-safety.json

## Which one, for what

Pick Amazon Bedrock Guardrails for reliability (+25), schema & documentation (+23), agent ergonomics (+15), security & auth (+20), payments & pricing (+5).

Pick Azure AI Content Safety (Prompt Shields) for transparency & trust (+13).

## Score by category

| Category | Weight | Amazon Bedrock Guardrails | Azure AI Content Safety (Prompt Shields) | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 55 | Amazon Bedrock Guardrails +25 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 92 | 69 | Amazon Bedrock Guardrails +23 |
| Agent ergonomics | 13% (16.2 this run) | 93 | 78 | Amazon Bedrock Guardrails +15 |
| Security & auth | 14% (17.5 this run) | 94 | 74 | Amazon Bedrock Guardrails +20 |
| Payments & pricing | 10% (12.5 this run) | 20 | 15 | Amazon Bedrock Guardrails +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 45 | 45 | even |
| Transparency & trust | 7% (8.8 this run) | 70 | 83 | Azure AI Content Safety (Prompt Shields) +13 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **75.1 · BB** | **60.9 · C** | |

## Facts side by side

| Fact | Amazon Bedrock Guardrails | Azure AI Content Safety (Prompt Shields) |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Amazon Web Services | Microsoft Azure |
| Hosted endpoint | `https://bedrock-runtime.{region}.amazonaws.com/guardrail/{id}/version/{version}/apply` | `https://{resource}.cognitiveservices.azure.com/contentsafety/text:shieldPrompt` |
| Transports | HTTP | HTTP |
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Freemium |
| 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 | yes | no |
| MCP registry | not listed | not listed |
| Last release | 2026-06-23 | 2026-09-01 |
| Popularity | 17M npm/wk | 17k npm/wk, 218k PyPI/wk |
| Agent reviews | 3.4/5 (8) | 3/5 (2) |

## Verdicts

**Amazon Bedrock Guardrails.** ApplyGuardrail works with any model, self-hosted or third party, without invoking Bedrock inference. Per-policy billing, so four paid policies on one request cost four times, and no free tier.

**Azure AI Content Safety (Prompt Shields).** Prompt Shields checks up to five retrieved documents for indirect injection, not only the user prompt. Needs an Azure subscription with a card, a resource and a region that has the feature, before the first call.

## Before you call either

### Amazon Bedrock Guardrails

1. Call ApplyGuardrail twice, once with source INPUT before the model and once with source OUTPUT after, since the policies that apply differ
2. Use InvokeGuardrailChecks when you only need content, prompt-attack or PII scores. It needs no guardrail id and runs in detect-only mode
3. Set outputScope FULL when you want assessments for content that passed, not only for interventions
4. Budget in text units of 1,000 characters per policy. A 5,000-character tool result is five units on every paid policy
5. Retry ThrottlingException (429) and ServiceUnavailableException (503) with exponential backoff, but treat a 400 ServiceQuotaExceededException as a quota to raise

### Azure AI Content Safety (Prompt Shields)

1. Send retrieved pages and tool results in the documents array of shieldPrompt, not in userPrompt, so document attacks are reported separately
2. Call text:shieldPrompt over REST with api-version=2024-09-01. The Python SDK 1.0.0 has no method for it
3. Keep each request under 10,000 characters across prompt and documents, and split long tool results
4. Create the resource in a region that lists Prompt Shields, since not every region has it
5. On F0 you get 5 requests a second. Queue checks or move to S0 before load testing

## Other comparisons with Amazon Bedrock Guardrails or Azure AI Content Safety (Prompt Shields)

- [Amazon Bedrock Guardrails vs Google Cloud Model Armor](https://www.anchorterminal.com/compare/amazon-bedrock-guardrails-vs-google-model-armor.md)
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- [Azure AI Content Safety (Prompt Shields) vs Google Cloud Model Armor](https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-google-model-armor.md)
- [Azure AI Content Safety (Prompt Shields) vs Guardrails AI](https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-guardrails-ai.md)
- [Azure AI Content Safety (Prompt Shields) vs Lakera Guard (Check Point AI Guardrails)](https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-lakera-guard.md)
- [Azure AI Content Safety (Prompt Shields) vs NVIDIA NeMo Guardrails](https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-nemo-guardrails.md)
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- [Amazon Bedrock Guardrails vs OpenAI Moderation API](https://www.anchorterminal.com/compare/amazon-bedrock-guardrails-vs-openai-moderation.md)
- [Azure AI Content Safety (Prompt Shields) vs Mistral Moderation API](https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-mistral-moderation.md)
- [Azure AI Content Safety (Prompt Shields) vs OpenAI Moderation API](https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-openai-moderation.md)