Last updated: 7 November 2026. Facts are vendor claims checked on that date; nothing was tested independently.

Promptfoo

The most widely used open-source LLM red-teaming tool. The paid tiers add dashboards, SSO and continuous monitoring. Buyers should note that it is now owned by a model vendor.

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What it tests

Claimed on the vendor's own pages. Nothing here was tested independently.

• Prompt injection
• Jailbreaks
• Data leakage
• Agent / tool abuse
• Bias, safety, harmful content
• Direct and indirect prompt injection
• PII
• Tool misuse, BOLA, SSRF
• 50+ vulnerability types

Framework mappings

OWASP LLM Top 10, NIST AI RMF, EU AI Act.

Offering

• MIT-licensed open-source CLI that the company says will remain open source.
• Red teaming covers 50+ vulnerability types.
• Paid tiers add dashboards, SSO and continuous monitoring.

Pricing

Public. Community tier free (up to 10k red-team probes a month); Enterprise and On-Prem custom. Free tier: yes. Community tier, up to 10k red-team probes a month. See what AI red teaming costs.

Ownership history

OpenAI's agreement to acquire Promptfoo was announced on 2026-03-09, subject to closing conditions at the time. Promptfoo's press page and GitHub README now say "Promptfoo is now part of OpenAI"; no closing date was found. The open-source CLI is MIT-licensed and "will remain open source".

Alternatives

Three vendors with a similar offering type and overlapping coverage. Chosen by category and claimed coverage, then alphabetically; no ranking is implied.

• Cisco AI Defense

  Automated platform Robust Intelligence acquired by Cisco

  Red teaming as a validation feature of a broad enterprise AI security suite.

• Enkrypt AI

  Automated platform Acquired by Anaconda

  Self-serve, credit-priced red teaming and guardrails with a free tier.

• Holistic AI

  Automated platform Independent

  Suited to buyers whose need is driven by compliance rather than by the security team.