# Fiddler Guardrails vs Promptfoo Guardrails: side-by-side comparison (2026)

[Fiddler Guardrails](https://cybersectools.com/tools/fiddler-guardrails) is a commercial [LLM guardrails](https://cybersectools.com/categories/llm-guardrails) solution by [Fiddler AI](https://cybersectools.com/companies/fiddler-ai). [Promptfoo Guardrails](https://cybersectools.com/tools/promptfoo-guardrails) is a commercial [LLM guardrails](https://cybersectools.com/categories/llm-guardrails) solution by [Promptfoo](https://cybersectools.com/companies/promptfoo). Features, integrations, deployment and the company behind each one, side by side.

## Side-by-side comparison

| | Fiddler Guardrails | Promptfoo Guardrails |
|---|---|---|
| Pricing model | Commercial | Commercial |
| Category | LLM Guardrails | LLM Guardrails |
| Verified | No | No |
| Deployment type | Hybrid | Hybrid |
| Company size fit | SMB, Mid-Market, Enterprise | Startup, SMB, Mid-Market, Enterprise |
| Company | Fiddler AI | Promptfoo |
| Headquarters | – | – |

### Use cases and capabilities

| | Fiddler Guardrails | Promptfoo Guardrails |
|---|---|---|
| Content Filtering | Yes | – |
| Generative AI | Yes | Yes |
| LLM Guardrails | – | Yes |
| LLM Security | – | Yes |
| AI Firewall | – | Yes |
| Prompt Injection | – | Yes |
| GenAI Security | – | Yes |
| Red Team | – | Yes |
| Continuous Testing | – | Yes |
| Adversarial ML | – | Yes |
| AI Governance | – | Yes |

### Core features

**Fiddler Guardrails**

9 features listed. Sign in on the page to see them.

**Promptfoo Guardrails**

6 features listed. Sign in on the page to see them.

### Integrations

**Fiddler Guardrails**

7 integrations listed. Sign in on the page to see them.

**Promptfoo Guardrails**

No integrations listed.

## Which one fits you

Based on what each listing shows: deployment, company size, price and open source.

- [Promptfoo Guardrails](https://cybersectools.com/tools/promptfoo-guardrails) fits if you are a startup.

## Fiddler Guardrails vs Promptfoo Guardrails FAQ

Common questions when comparing Fiddler Guardrails vs Promptfoo Guardrails for LLM guardrails.

### What is the difference between Fiddler Guardrails and Promptfoo Guardrails?

**Fiddler Guardrails**: Guardrails for protecting LLM and agentic applications from harmful content. Built by Fiddler AI.

**Promptfoo Guardrails**: Adaptive LLM guardrails that self-improve via red team feedback loops. Built by Promptfoo.

The table above shows where their features, integrations, deployment and company size fit differ.

### Who makes Fiddler Guardrails and Promptfoo Guardrails?

**Fiddler Guardrails** is made by Fiddler AI. **Promptfoo Guardrails** is made by Promptfoo. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is Fiddler Guardrails a good alternative to Promptfoo Guardrails?

Often, yes. Fiddler Guardrails and Promptfoo Guardrails are both LLM Guardrails products, and both cover Generative AI. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [Fiddler Guardrails vs RealmGuard](https://cybersectools.com/compare/fiddler-guardrails-vs-realm-labs-platform)
- [Fiddler Guardrails vs First Recon AI Firewall](https://cybersectools.com/compare/fiddler-guardrails-vs-first-recon-ai-firewall)
- [Fiddler Guardrails vs Airia AI Platform Guardrails](https://cybersectools.com/compare/airia-ai-platform-guardrails-vs-fiddler-guardrails)
- [Promptfoo Guardrails vs RealmGuard](https://cybersectools.com/compare/promptfoo-guardrails-vs-realm-labs-platform)
- [Promptfoo Guardrails vs First Recon AI Firewall](https://cybersectools.com/compare/first-recon-ai-firewall-vs-promptfoo-guardrails)
- [Promptfoo Guardrails vs Airia AI Platform Guardrails](https://cybersectools.com/compare/airia-ai-platform-guardrails-vs-promptfoo-guardrails)

## Alternatives to each

- [See all Fiddler Guardrails alternatives](https://cybersectools.com/alternatives/fiddler-guardrails)
- [See all Promptfoo Guardrails alternatives](https://cybersectools.com/alternatives/promptfoo-guardrails)

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Source: https://cybersectools.com/compare/fiddler-guardrails-vs-promptfoo-guardrails

For AI agents: each product above has its own Markdown page (add .md to its URL, for example https://cybersectools.com/tools/fiddler-guardrails.md). Every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md.

More on Fiddler Guardrails and Promptfoo Guardrails: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md