# Promptfoo

Startup profile on Capital Atlas: https://capitalatlas.ai/startups/promptfoo

- Industry: Software
- Headquarters: San Francisco, US
- Website: www.promptfoo.dev/
- Total disclosed funding: $23M
- Latest round: Series A (Jul 1, 2025)
- Investors on record: 2

## About

Based in California, US, and founded in 2024 by Ian Webster and Michael D'Angelo, Promptfoo operates as a large language models testing company that develops open-source tools to help developers identify and address vulnerabilities in AI applications. Their core product offering includes an automated pentesting service designed to identify security, legal, and brand risks within LLM applications. Promptfoo provides custom probes targeting vulnerabilities of interest to developers, such as prompt injections and jailbreaks. The platform operates through a command-line interface for quick deployment and integration, serving over 25,000 developers worldwide, particularly in North America and Europe. Promptfoo generates revenue predominantly through a subscription-based model, offering tiered access to its LLM testing tools. Transactions typically involve annual or monthly subscriptions, priced to accommodate both small development teams and larger enterprises. In March 2026, OpenAI, a portfolio company of Al Moammar Information Systems Co., Altimeter Capital, Amazon, Andreessen Horowitz, Anti Fund, Ark Invest, Bedrock, Blackstone, Boman Group, CalPERS - California Public Employees' Retirement System, Coatue Management, D1 Capital Partners, Dragoneer Investment Group, Fidelity Investments, Founders Fund, K2 Global, Khosla Ventures, Magnetar Capital, MGX, Microsoft, NVIDIA Corporation, Pengana Capital Group, Quiet Capital, SB Investment Advisers, Sequoia Capital, T Rowe Price, The Walt Disney Company, Thrive Capital, Tiger Global Management, Tioex Technologies, TPG, and Wisdom Ventures, agreed to acquire Promptfoo Inc. from Andreessen Horowitz and Insight Partners. Financial terms were not disclosed. The March 2026 acquisition will enable to incorporate Promptfoo’s technology into OpenAI Frontier so that businesses can evaluate agent actions, identify potential risks prior to launch, and keep documentation to facilitate oversight, governance, and accountability.

## Funding rounds

- Series A, Jul 1, 2025, $18M — Insight Partners, Andreessen Horowitz
- Seed, Jul 23, 2024, $5M — Andreessen Horowitz

## Investors

- Andreessen Horowitz (https://capitalatlas.ai/funds/andreessen-horowitz) — Seed, Series A
- Insight Partners (https://capitalatlas.ai/funds/insight-partners) — Series A