CISO Tribune

Vendor comparison · 2 companies

Promptfoo vs Tenzai

Promptfoo builds open-source tools for secure, reliable AI applications. Tenzai sells an AI agentic penetration testing platform that hacks, exploits and fixes vulnerabilities across enterprise software. CISO Tribune files both under Breach simulation and automated pen-testing. This page sets the two records side by side: what each sells, where it is based, who owns and funds it, the customers it names and its recent news, each fact numbered to its source.

Change the companies

Up to four companies side by side.

  • Promptfoo
  • Tenzai
Promptfoo vs Tenzai: Products, Customers and Funding Compared
PromptfooPromptfoo builds open-source tools for secure, reliable AI applications.promptfoo.devTenzaiTenzai sells an AI agentic penetration testing platform that hacks, exploits and fixes vulnerabilities across enterprise software.tenzai.com
What it sells
  • Red Teaming[2][4][5]Simulates real users to uncover application-specific vulnerabilities.
  • Evaluations[2][5]LLM evaluation of prompts and models that can run inside CI workflows.
  • Tenzai[1][3][4][5]An AI agentic penetration testing platform for enterprise software. It discovers exploitable attack chains across web app, mobile, AI, external and internal network attack surfaces.
Categories
Headquarters
San Francisco, United States[1][3]Not stated on its pages
Founded
2024[1][12]2025[2][4][5]
Ownership and funding
Owned by OpenAI[12]Privately held[3]
Named customers
Not stated on its pagesNot stated on its pages
Recent news
  • March 9, 2026OpenAI agreed to buy Promptfoo, a startup helping businesses find and fix security issues in AI models during development.[13]
  • March 9, 2026OpenAI announced it has acquired Promptfoo, an AI security startup founded in 2024 to protect LLMs from adversarial attacks.[12]
Not stated on its pages
G2 and Gartner Peer Insights
  • G2: Not stated on its pages
  • Gartner Peer Insights: Not stated on its pages
  • G2: Not stated on its pages
  • Gartner Peer Insights: Not stated on its pages
Who it fits
Not written yetIts pages describe an application security team that tests APIs reaching PCI-scoped and critical systems. Tenzai is also described as a way for teams to verify scanner and bug-bounty findings and gather evidence for follow-up. Security teams can match sets of frontier and open-weight models to each test type or application risk level.
Last verified
November 4, 2026November 8, 2026

Where they overlap

  • Promptfoo and Tenzai are both filed under Breach simulation and automated pen-testing.

Where they differ, field by field

  • Promptfoo's primary category is AI model and agent security; Tenzai's is Breach simulation and automated pen-testing.
  • Promptfoo is also filed under AI firewalls and guardrails and Static application security testing. Tenzai is also filed under Penetration testing and red team services.
  • Promptfoo lists Red Teaming and Evaluations. Tenzai lists Tenzai.
  • Promptfoo is headquartered in San Francisco, United States.
  • Promptfoo was founded in 2024. Tenzai was founded in 2025.
  • Promptfoo is owned by OpenAI. Tenzai is privately held.

What it sells: Promptfoo

What Red Teaming does[2][4][5]
Promptfoo creates thousands of context-aware attacks tailored to the customer's application. The open-source Community version includes up to 10k probes per month at no charge.
What Evaluations does[2][5]
Promptfoo's LLM evaluation can be integrated into a CircleCI pipeline. Promptfoo can be integrated with test frameworks like Jest and Vitest to evaluate prompts as part of existing testing and CI workflows. Promptfoo provides real-time alerts and automated evaluations to show LLM security status across all projects.

What it sells: Tenzai

What Tenzai does[1][3][4][5]
Tenzai's agents are engineered to learn the business purpose and workflows of applications. Tenzai starts autonomous tests in black, gray or white box modes. Tenzai blocks exploitation with a hardened WAF rule that is validated for the customer's environment, ahead of a permanent fix. Tenzai offers step-by-step guidance, coding-assistant prompts and ticket creation for remediation.

Questions about Promptfoo and Tenzai

What do Promptfoo and Tenzai sell?
Promptfoo sells Red Teaming and Evaluations. Tenzai sells Tenzai.
Are Promptfoo and Tenzai in the same category?
They share Breach simulation and automated pen-testing. Promptfoo's primary category is AI model and agent security and Tenzai's is Breach simulation and automated pen-testing.
Where are Promptfoo and Tenzai headquartered?
Promptfoo is headquartered in San Francisco, United States.
When were Promptfoo and Tenzai founded?
Promptfoo was founded in 2024. Tenzai was founded in 2025.
Who owns Promptfoo and Tenzai?
Promptfoo is owned by OpenAI. Tenzai is privately held.
Who are Promptfoo and Tenzai sold to?
Its pages describe an application security team that tests APIs reaching PCI-scoped and critical systems.
What have Promptfoo and Tenzai announced recently?
March 9, 2026: OpenAI agreed to buy Promptfoo, a startup helping businesses find and fix security issues in AI models during development.

About Promptfoo

Promptfoo builds open-source tools for secure, reliable AI applications. Promptfoo is based in San Francisco, California, and is now part of OpenAI. Investors and operators backed Promptfoo early, and Promptfoo builds open-source, application-focused AI security.

Promptfoo's red teaming simulates real users to uncover application-specific vulnerabilities. Promptfoo creates thousands of context-aware attacks tailored to the customer's application. Promptfoo says its tests understand business logic, RAG, agents and integrations, and cover 50+ vulnerability types from injection to jailbreaks.[4]

Promptfoo connects to AI apps, agents, and workflows. Promptfoo provides remediation guidance directly in pull requests and developer workflows. Promptfoo lets teams track remediation progress and get suggested steps for each issue.[4][5]

The Community version includes all core features for local testing, evaluation, and vulnerability scanning. The open-source Community version includes up to 10k probes per month at no charge. Enterprise customers can purchase additional probes for larger scale testing. Enterprise pricing is customized based on a team's size and needs.[5]

Promptfoo lets customers manage LLM applications with teams-based access control and SSO, granular permission profiles, and customizable API access. Promptfoo provides real-time alerts and automated evaluations to show LLM security status across all projects. Promptfoo supports customizable plugin collections, scan configurations, and target settings that can be shared among colleagues.[5]

Promptfoo's LLM evaluation can be integrated into a CircleCI pipeline. Promptfoo can be integrated with test frameworks like Jest and Vitest to evaluate prompts as part of existing testing and CI workflows. Promptfoo's application-level jailbreak creation can be integrated with Burp Suite's Intruder feature for security testing of LLM-powered applications. Promptfoo can import eval test cases directly from Microsoft SharePoint CSV files using certificate-based authentication with Azure AD. Promptfoo configurations can reference prompts managed in Langfuse.[6][7][8][9][10]

Promptfoo offers real estate plugins that test every AI touchpoint, from property search to lending to advertising, across all 7 federally protected classes. Promptfoo tests AVM and appraisal AI for demographic correlation in valuations. Promptfoo's real estate testing covers home search assistants, neighborhood recommendation engines, property matching tools, and school district comparison features. Promptfoo's real estate testing can run entirely within a customer's infrastructure, with no applicant or transaction data leaving the environment. Promptfoo integrates with CI/CD pipelines to catch fair housing regressions before deployment. Promptfoo generates structured reports that map directly to Fair Housing Act and ECOA requirements.[11]

Promptfoo says its contributors are from companies like OpenAI, Google, Microsoft, and Amazon.[2][4][5][6][11]

Promptfoo on the record

Sources

Promptfoo full record

  1. [1]PressPromptfoo · promptfoo.dev · undated page, accessed November 4, 2026 · Tier A
  2. [2]promptfoo.devPromptfoo · promptfoo.dev · undated page, accessed November 4, 2026 · Tier A
  3. [3]About Promptfoo | AI Security Experts | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  4. [4]Build Secure AI Applications | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  5. [5]Pricing | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  6. [6]Setting up Promptfoo with CircleCI | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  7. [7]Testing prompts with Jest and Vitest | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  8. [8]Finding LLM Jailbreaks with Burp Suite | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  9. [9]SharePoint Integration | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  10. [10]Langfuse integration | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  11. [11]AI Security for Real Estate | PromptfooPromptfoo · undated page, accessed November 10, 2026 · Tier A
  12. [12]OpenAI acquires Promptfoo to secure its AI agents | TechCrunchTechCrunch · published March 9, 2026 · Tier B
  13. [13]OpenAI Buying AI Security Startup Promptfoo to Safeguard AI Agents - BloombergBloomberg · published March 9, 2026 · Tier B

Tenzai full record

  1. [1]Ahead partners with tenzai to strengthen cyber resilience with ai enabled penetration testingTenzai · tenzai.com · published July 23, 2026 · Tier A
  2. [2]tenzai.comTenzai · tenzai.com · undated page, accessed November 8, 2026 · Tier A
  3. [3]Tenzai: Your ultimate AI hacker teammateTenzai · undated page, accessed November 8, 2026 · Tier A
  4. [4]About Tenzai | AI Hacker for Autonomous PentestingTenzai · undated page, accessed November 10, 2026 · Tier A
  5. [5]Tenzai | AI Hacker for EnterpriseTenzai · undated page, accessed November 10, 2026 · Tier A

Spot a factual error? Request a correction.