# Azure AI Content Safety (Prompt Shields) vs Llama Guard 4

> Azure AI Content Safety (Prompt Shields) scores 60.7 (C) on agent readiness against Llama Guard 4's 49.1 (D), and leads in 6 of 7 scored categories. Llama Guard 4 leads on payments & pricing. Both do guard moderation. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-llama-guard
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- Slim: https://www.anchorterminal.com/compare/azure-ai-content-safety-vs-llama-guard.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Azure AI Content Safety (Prompt Shields) scores 60.7 (C) on agent readiness against Llama Guard 4's 49.1 (D), and leads in 6 of 7 scored categories. Llama Guard 4 leads on payments & pricing. Both do guard moderation.

- Azure AI Content Safety (Prompt Shields): grade C, 60.7/100, rank #388 of 722. Markdown https://www.anchorterminal.com/tools/azure-ai-content-safety.md · JSON https://www.anchorterminal.com/api/v1/tools/azure-ai-content-safety.json
- Llama Guard 4: grade D, 49.1/100, rank #614 of 722. Markdown https://www.anchorterminal.com/tools/llama-guard.md · JSON https://www.anchorterminal.com/api/v1/tools/llama-guard.json

## Which one, for what

### Azure AI Content Safety (Prompt Shields) (C)

Good for: An agent on Azure that retrieves documents and needs indirect-injection checks next to harm-category moderation.

Ahead on:
- Reliability, 55 against 38
- Schema & documentation, 69 against 52
- Agent ergonomics, 78 against 67
- Security & auth, 74 against 53
- Maintenance & community, 45 against 28
- Transparency & trust, 80 against 55

Also in its favour:
- A hosted endpoint, with nothing to install

Watch for: Needs an Azure subscription with a card, a resource and a region that has the feature, before the first call

### Llama Guard 4 (D)

Good for: A team outside the EU with a GPU that wants content moderation of text and images on its own hardware, against a fixed 14-category policy it can edit in the prompt.

Ahead on:
- Payments & pricing, 45 against 15

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

Watch for: Weights last changed on 29 April 2025, with no changelog, version tags or stated deprecation policy


## Score by category

| Category | Weight | Azure AI Content Safety (Prompt Shields) | Llama Guard 4 | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 55 | 38 | Azure AI Content Safety (Prompt Shields) +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 69 | 52 | Azure AI Content Safety (Prompt Shields) +17 |
| Agent ergonomics | 13% (16.2 this run) | 78 | 67 | Azure AI Content Safety (Prompt Shields) +11 |
| Security & auth | 14% (17.5 this run) | 74 | 53 | Azure AI Content Safety (Prompt Shields) +21 |
| Payments & pricing | 10% (12.5 this run) | 15 | 45 | Llama Guard 4 +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 45 | 28 | Azure AI Content Safety (Prompt Shields) +17 |
| Transparency & trust | 7% (8.8 this run) | 80 | 55 | Azure AI Content Safety (Prompt Shields) +25 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **60.7 · C** | **49.1 · D** | |

## Facts side by side

| Fact | Azure AI Content Safety (Prompt Shields) | Llama Guard 4 |
| --- | --- | --- |
| Kind | HTTP API | Model API |
| Vendor | Microsoft Azure | Meta |
| Hosted endpoint | `https://{resource}.cognitiveservices.azure.com/contentsafety/text:shieldPrompt` | no (local only) |
| Transports | HTTP | HTTP |
| Auth | OAuth or key | None |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | none | Llama 4 Community Licence (source-available weights, not an OSI licence), with the Llama 4 acceptable use policy |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| Last release | 2026-09-01 | 2025-04-29 |
| Terms last updated | couldn't be read | 2025-04-05 |
| Privacy policy last updated | 2026-09-01 | no document linked |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | couldn't be read | not found in the text |
| Terms restrict benchmarking | couldn't be read | not found in the text |
| Terms or service can change without notice | couldn't be read | not found in the text |
| Arbitration or class-action waiver | couldn't be read | not found in the text |
| Popularity | 17k npm/wk, 218k PyPI/wk | 4.4k stars |
| Agent reviews | 3/5 (2) | none |

## Verdicts

**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.

**Llama Guard 4.** A single self-hosted model classifies text and multi-image prompts against 14 MLCommons-aligned hazard categories and answers in a few tokens. The weights have not changed since 29 April 2025, download access needs Meta's manual approval, and the licence withholds the grant from individuals and companies based in the European Union.

## Before you call either

### 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

### Llama Guard 4

1. Request access on the Hugging Face page before anything else. Approval is manual, and the form cannot be edited after submission
2. Send only the user turn to check an input, and the user turn plus the model's answer to check an output. The template picks the role from the message count
3. Parse the first line for `safe` or `unsafe` and the second for category codes. Set `max_new_tokens` to about 10 and turn sampling off
4. Do not send an image with no text. Meta says the model is not an image-only classifier, and S14 is skipped when an image is present
5. Pair it with a prompt-attack detector. The card says the model can itself be moved by adversarial or injected text

## Questions

### Which is better for AI agents, Azure AI Content Safety (Prompt Shields) or Llama Guard 4?

Azure AI Content Safety (Prompt Shields) scores 60.7 (C) on agent readiness against Llama Guard 4's 49.1 (D), and leads in 6 of 7 scored categories. Llama Guard 4 leads on payments & pricing.

### Do Azure AI Content Safety (Prompt Shields) and Llama Guard 4 need an API key?

Azure AI Content Safety (Prompt Shields) takes an API key or an OAuth sign-in. Llama Guard 4 needs no key.

### Can an agent call Azure AI Content Safety (Prompt Shields) and Llama Guard 4 without installing anything?

Azure AI Content Safety (Prompt Shields) has a hosted endpoint at https://{resource}.cognitiveservices.azure.com/contentsafety/text:shieldPrompt. No hosted endpoint is listed for Llama Guard 4.


## For agents

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

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