Promptfoo — Funding & Company Data

Promptfoo executed a rapid and successful funding trajectory, securing a $5 million Seed round in July 2024 led by Andreessen Horowitz, which included prominent angel investors like the CEOs of Shopify and Okta. This was quickly followed by a substantial $18.4 million Series A just one year later, led by Insight Partners, which valued the company at $86 million. This swift fundraising from top-tier VCs highlights significant market confidence in their open-source approach to AI security and evaluation, a critical pain point for enterprises deploying large language models.

The investor quality is exceptionally high, with two of the most respected firms in software and AI leading the rounds. This backing provided not just capital but also immense validation, which likely accelerated its adoption among Fortune 500 companies. The funding enabled the company to scale its team and platform development to meet strong enterprise demand.

The culmination of this trajectory was the acquisition by OpenAI in March 2026. While the financial terms were not disclosed, the acquisition by the leader in the AI space serves as the ultimate validation of Promptfoo's technology and team. For OpenAI, the deal brings critical, battle-tested AI security and evaluation tools in-house, addressing a major barrier to enterprise AI adoption. The decision to keep the core product open-source post-acquisition suggests a strategy to maintain its widespread developer adoption and position it as an industry standard, now with the backing and resources of a major AI lab.