CISO Tribune

Vendor comparison · 2 companies

Horizon3.ai vs Promptfoo

Horizon3.ai sells NodeZero, a platform that autonomously executes real attack techniques in production environments so organizations can find exploitable weaknesses, fix them and verify the fixes. Promptfoo builds open-source tools for secure, reliable AI applications. 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.

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  • Horizon3.ai
  • Promptfoo
Horizon3.ai vs Promptfoo: Products, Customers and Funding Compared
Horizon3.aiHorizon3.ai sells NodeZero, a platform that autonomously executes real attack techniques in production environments so organizations can find exploitable weaknesses, fix them and verify the fixes.horizon3.aiPromptfooPromptfoo builds open-source tools for secure, reliable AI applications.promptfoo.dev
What it sells
  • NodeZero[2][3][5][6][7][8][9][10][14]An autonomous platform that executes real attack techniques in production.
  • Endpoint Security Effectiveness[3][7]Tests how endpoint protections respond to real attack behavior.
  • 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.
Categories
Headquarters
San Francisco, United States[1][11]San Francisco, United States[1][3]
Founded
2019[1][11]2024[1][12]
Ownership and funding
Privately held[2][3]Owned by OpenAI[12]
Named customers
Not stated on its pagesNot stated on its pages
Recent news
  • November 5, 2026Horizon3 appointed Chris Wood as Director of Sales for Australia and New Zealand and Vivienne Horsfall as Growth Marketing Director for Asia Pacific and Japan.[13]
  • July 29, 2026Horizon3 announced an expansion of its NodeZero platform to include AI-powered web application pentesting capabilities.[14]
  • July 15, 2026Horizon3 announced it is taking part in Anthropic's Project Glasswing, an initiative focused on securing critical infrastructure.[12]
  • 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]
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
From its own pages, Horizon3.ai sells mainly to security teams that want to test their defenses with real attacks in production. It names banks, healthcare systems, energy providers, manufacturers, governments and defense contractors as organizations that rely on NodeZero. Its pages describe customers ranging from the Global 100 to a local hospital.Not written yet
Last verified
September 27, 2026November 4, 2026

Where they overlap

  • Horizon3.ai and Promptfoo are both filed under Breach simulation and automated pen-testing.
  • Both are headquartered in San Francisco, United States.

Where they differ, field by field

  • Horizon3.ai's primary category is Breach simulation and automated pen-testing; Promptfoo's is AI model and agent security.
  • Promptfoo is also filed under AI firewalls and guardrails and Static application security testing.
  • Horizon3.ai lists NodeZero and Endpoint Security Effectiveness. Promptfoo lists Red Teaming and Evaluations.
  • Horizon3.ai was founded in 2019. Promptfoo was founded in 2024.
  • Horizon3.ai is privately held. Promptfoo is owned by OpenAI.

What it sells: Horizon3.ai

What NodeZero does[2][3][5][6][7][8][9][10][14]
NodeZero is described as an autonomous platform capable of executing self-directed actions to achieve an objective. Horizon3.ai says it executes real attack techniques without agents or disruption. It is delivered via multi-tenant SaaS.
What Endpoint Security Effectiveness does[3][7]
NodeZero checks for EDR presence on each host. It then executes techniques ranging from credential theft to privilege escalation and lateral movement. Every action is mapped to a MITRE ATT&CK TTP and labeled blocked or permitted.

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.

Questions about Horizon3.ai and Promptfoo

What do Horizon3.ai and Promptfoo sell?
Horizon3.ai sells NodeZero and Endpoint Security Effectiveness. Promptfoo sells Red Teaming and Evaluations.
Are Horizon3.ai and Promptfoo in the same category?
They share Breach simulation and automated pen-testing. Horizon3.ai's primary category is Breach simulation and automated pen-testing and Promptfoo's is AI model and agent security.
Where are Horizon3.ai and Promptfoo headquartered?
Both are headquartered in San Francisco, United States.
When were Horizon3.ai and Promptfoo founded?
Horizon3.ai was founded in 2019. Promptfoo was founded in 2024.
Who owns Horizon3.ai and Promptfoo?
Horizon3.ai is privately held. Promptfoo is owned by OpenAI.
Who are Horizon3.ai and Promptfoo sold to?
From its own pages, Horizon3.ai sells mainly to security teams that want to test their defenses with real attacks in production.
What have Horizon3.ai and Promptfoo announced recently?
November 5, 2026: Horizon3 appointed Chris Wood as Director of Sales for Australia and New Zealand and Vivienne Horsfall as Growth Marketing Director for Asia Pacific and Japan. March 9, 2026: OpenAI agreed to buy Promptfoo, a startup helping businesses find and fix security issues in AI models during development.

About Horizon3.ai

Horizon3.ai sells NodeZero, a platform that autonomously executes real attack techniques in production environments so organizations can find exploitable weaknesses, fix them and verify the fixes.

Horizon3.ai describes the problem as one of effectiveness. Its pages say that security teams do not have a tools problem, and that many siloed security tools are not designed to work together. The company says the seams between those tools are blind spots that attackers exploit. Horizon3.ai says knowing a vulnerability exists is not enough and that teams need to know whether it is actually exploitable.[5]

NodeZero is described as an autonomous platform capable of executing self-directed actions to achieve an objective. In pentesting, those objectives include becoming Domain Admin, compromising sensitive data and gaining access to critical systems. Horizon3.ai says NodeZero executes real attack techniques without agents or disruption. Horizon3.ai says its autonomous approach is delivered via multi-tenant SaaS.[5]

Horizon3.ai describes a loop of hack, fix, verify and repeat. Its pages say teams should re-test to confirm a threat is gone after a fix. The company also describes a one-click verify tool in NodeZero that starts a targeted retest.[6]

Endpoint Security Effectiveness shows how endpoint protections respond to real attack behavior, and NodeZero checks for EDR presence on each host. Horizon3.ai also sells pentesting for compliance, delivered by OSCP pentesters together with the NodeZero platform.[6][7]

The service delivers a Penetration Test Report and a Fix Action Report.[6]

Horizon3.ai says NodeZero serves customers from the Global 100 to a local hospital. Its pages also name banks, healthcare systems, energy providers, manufacturers, governments and defense contractors as organizations that rely on NodeZero.[5][9]

Horizon3.ai was founded in 2019 and is headquartered in San Francisco, CA. Snehal Antani is its Co-Founder and CEO. The company describes its team as a mix of US Special Operations, US National Security and cybersecurity industry veterans.[4][6][7][8][10]

Horizon3.ai on the record

Sources

Horizon3.ai full record

  1. [1]About usHorizon3.ai · horizon3.ai · undated page, accessed September 27, 2026 · Tier A
  2. [2]Horizon3 raises 250m series e at 2b valuation to lead the ai vs ai cybersecurity eraHorizon3.ai · horizon3.ai · published August 3, 2026 · Tier A
  3. [3]Home | Horizon3.aiHorizon3.ai · undated page, accessed October 25, 2026 · Tier A
  4. [4]Why Continuous Exposure Management Matters for Financial ServicesHorizon3.ai · undated page, accessed October 25, 2026 · Tier A
  5. [5]The Future of Security: Our Vision | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  6. [6]Compliance Solutions for Cybersecurity | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  7. [7]Endpoint Security Effectiveness | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  8. [8]Identity Security Validation | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  9. [9]Why Our Platform Wins | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  10. [10]HomeECB AI Cybersecurity Mandate | NodeZero® | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  11. [11]The Team | Horizon3Horizon3.ai · undated page, accessed November 5, 2026 · Tier A
  12. [12]Horizon3 Joins Anthropic’s Project Glasswing to Help Defend Critical Infrastructure with the Attacker’s PerspectiveHorizon3 · published July 15, 2026 · Tier A
  13. [13]Horizon3 Expands Australia and New Zealand Team, Strengthens APJ InvestmentHorizon3 · published November 5, 2026 · Tier A
  14. [14]Horizon3’s NodeZero® AI Hacker Extends Production-Safe Autonomous Pentesting to Web ApplicationsHorizon3 · published July 29, 2026 · Tier A

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

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