HiddenLayer vs Promptfoo

HiddenLayer is an Austin, Texas-based AI security company founded in March 2022 by experienced cybersecurity and machine learning professionals. The company provides a comprehensive AI Security Platform covering AI Discovery (automated inventory), AI Supply Chain Security (model scanning for embedded threats), AI Attack Simulation (red teaming), and AI Runtime Security (guardrails and active threat response). The platform is designed to be non-invasive — protecting models without requiring access to raw training data — and integrates with CI/CD, MLOps, data pipelines, and SIEM/SOAR tools. HiddenLayer is recognized by Gartner as a Cool Vendor for AI Application Security. The company raised $50M in Series A in September 2023, the largest Series A for an AI-focused cybersecurity company at that time, led by M12 (Microsoft's Venture Fund) and Moore Strategic Ventures. Customers include enterprises in financial services, US federal government, and technology. Named endorsers include the CISO of the NFL and the former CISO of AIG.

Promptfoo is an open-source CLI and library for evaluating LLM prompts, models, RAGs, and agents through automated benchmarks and matrix comparisons, alongside red-teaming for security vulnerabilities like prompt injections, jailbreaks, PII leaks, and insecure tool use. It differentiates via developer-first local execution, CI/CD integration, and modular plugins covering 50+ attack types with community-driven threat intelligence. Targeted at developers and security teams in enterprises (127 Fortune 500 users), it supports self-hosting to avoid vendor lock-in. Enterprise adds collaboration, monitoring, SSO, and compliance dashboards. Acquired by OpenAI in March 2026 for integration into Frontier platform, remains open-source with SaaS/on-prem options.Promptfoo homepagePromptfoo docsPromptfoo pricing