HiddenLayer vs Promptfoo

Both compete in Red-Teaming & AI Security. HiddenLayer positions itself as “AI detection and response plus red teaming to protect machine learning models and AI products”, while Promptfooleads with “Open-source tool for evaluating and red-teaming LLM apps, agents, and RAG systems”. The table below compares what each publishes.

Where HiddenLayer pulls ahead

Enterprises and regulated organizations needing runtime protection and detection for production ML models

Where Promptfoo pulls ahead

Developer teams wanting free, open-source, CI/CD-integrated evaluation and red teaming of LLM apps

	HiddenLayer	Promptfoo
Positioning	AI detection and response plus red teaming to protect machine learning models and AI products	Open-source tool for evaluating and red-teaming LLM apps, agents, and RAG systems
Category	Red-Teaming & AI Security	Red-Teaming & AI Security
Frameworks	None published	None published
Deployment	SaaS, On-prem, API	Open-source, SaaS, API
Built for	Security, Data Science / ML, Risk	Data Science / ML, Security
Founded	2022	2023
Headquarters	Austin, Texas, USA	USA
Ownership	Private (VC-backed)	Acquired by OpenAI (2026); previously VC-backed
Funding	$56M total; $50M Series A in 2023 led by M12 and Moore Strategic Ventures, with Booz Allen, IBM and Capital One Ventures	~$23.4M raised prior to acquisition; $5M seed (a16z, 2024) and $18.4M Series A led by Insight Partners (2025)
Pricing	Not published	Open-source (MIT license), free; paid enterprise platform
Key capabilities	Machine Learning Detection and Response (MLDR) Model scanning Automated red teaming Real-time attack detection AI risk and governance reporting Response actions (alert, isolate, deceive)	LLM evaluation and benchmarking Automated red teaming and vulnerability scanning Declarative test configs Prompt and model comparison CI/CD integration Local/self-hosted execution
Integrations	Not published	OpenAI, Anthropic, Google Gemini, DeepSeek, CI/CD pipelines, GitHub
Notable customers	None published	OpenAI, Anthropic, Fortune 500 enterprises
Best for	Enterprises and regulated organizations needing runtime protection and detection for production ML models	Developer teams wanting free, open-source, CI/CD-integrated evaluation and red teaming of LLM apps
Limitations	Historically ML-model centric; buyers seeking full agentic AI governance or compliance certification may need complementary tooling.	Developer-oriented and requires engineering effort to configure; broader governance/compliance features live in the paid enterprise tier.

Which should you shortlist?

Choose HiddenLayer if enterprises and regulated organizations needing runtime protection and detection for production ML models

Choose Promptfoo if developer teams wanting free, open-source, CI/CD-integrated evaluation and red teaming of LLM apps

Neither is a substitute for a governance program. Whichever you pick, you still need people who can define the policies the tool enforces.

Full HiddenLayer profile →Full Promptfoo profile →

AI Governance Tool Selection Kit

A vendor-comparison worksheet plus EU AI Act, NIST AI RMF and ISO/IEC 42001 requirement checklists — so you can shortlist tools against the obligations that actually apply to you.

Free. No spam — unsubscribe anytime.