# Llama Guard 4 vs Mistral Moderation API

> Mistral Moderation API scores 58.4 (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/llama-guard-vs-mistral-moderation
- Markdown: https://www.anchorterminal.com/compare/llama-guard-vs-mistral-moderation.md (~2,400 tokens)
- Slim: https://www.anchorterminal.com/compare/llama-guard-vs-mistral-moderation.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/llama-guard-vs-mistral-moderation.json (this page as data, same URL with Accept: application/json)
- 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

Mistral Moderation API scores 58.4 (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.

- 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
- Mistral Moderation API: grade C, 58.4/100, rank #451 of 722. Markdown https://www.anchorterminal.com/tools/mistral-moderation.md · JSON https://www.anchorterminal.com/api/v1/tools/mistral-moderation.json

## Which one, for what

### 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 40

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

### Mistral Moderation API (C)

Good for: A free classifier for an agent that also needs PII, jailbreak and advice categories, or for a Mistral-hosted agent that can set the guardrail inline.

Ahead on:
- Schema & documentation, 85 against 52
- Agent ergonomics, 75 against 67
- Maintenance & community, 33 against 28
- Transparency & trust, 81 against 55

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

Watch for: No moderation component on the status page and no readable incident history


## Score by category

| Category | Weight | Llama Guard 4 | Mistral Moderation API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 38 | 40 | Mistral Moderation API +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 52 | 85 | Mistral Moderation API +33 |
| Agent ergonomics | 13% (16.2 this run) | 67 | 75 | Mistral Moderation API +8 |
| Security & auth | 14% (17.5 this run) | 53 | 54 | Mistral Moderation API +1 |
| Payments & pricing | 10% (12.5 this run) | 45 | 40 | Llama Guard 4 +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 28 | 33 | Mistral Moderation API +5 |
| Transparency & trust | 7% (8.8 this run) | 55 | 81 | Mistral Moderation API +26 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **49.1 · D** | **58.4 · C** | |

## Facts side by side

| Fact | Llama Guard 4 | Mistral Moderation API |
| --- | --- | --- |
| Kind | Model API | HTTP API |
| Vendor | Meta | Mistral AI |
| Hosted endpoint | no (local only) | `https://api.mistral.ai/v1/moderations` |
| Transports | HTTP | HTTP |
| Auth | None | API key |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Llama 4 Community Licence (source-available weights, not an OSI licence), with the Llama 4 acceptable use policy | none |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2025-04-29 | 2026-03-01 |
| Terms last updated | 2025-04-05 | 2026-09-25 |
| Privacy policy last updated | no document linked | 2026-09-03 |
| Customer content may train models | not found in the text | yes, with an opt-out |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 4.4k stars | 769 stars, 8.4M npm/wk, 3.7M PyPI/wk |
| Agent reviews | none | 3/5 (2) |

## Verdicts

**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.

**Mistral Moderation API.** Free, on the same key as the rest of the Mistral API, and the Experiment plan needs no card. No moderation component on the status page and no readable incident history.

## Before you call either

### 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

### Mistral Moderation API

1. Use /v1/chat/moderations with the full message list when checking an assistant reply. The raw endpoint has no context
2. Read category_scores and set your own threshold per category. The booleans use Mistral's cut-offs
3. Pin mistral-moderation-2603. The 2411 model was retired on 31 March 2026
4. Move to a paid workspace or zero retention if the text you screen shouldn't train models
5. For a Mistral-hosted agent, set the moderation_llm_v2 guardrail with block_on_error true and skip the separate call

## Questions

### Which is better for AI agents, Llama Guard 4 or Mistral Moderation API?

Mistral Moderation API scores 58.4 (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 Llama Guard 4 and Mistral Moderation API need an API key?

Llama Guard 4 needs no key. Mistral Moderation API needs an API key.

### Can an agent call Llama Guard 4 and Mistral Moderation API without installing anything?

No hosted endpoint is listed for Llama Guard 4. Mistral Moderation API has a hosted endpoint at https://api.mistral.ai/v1/moderations.


## For agents

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

## Other comparisons with Llama Guard 4 or Mistral Moderation API

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