What is OpenAI?
A plain-English primer on OpenAI: what it builds, who founded it, how it is structured, and why investors are watching its path to the public markets.
OpenAI is an AI research and deployment company and the maker of ChatGPT and the GPT family of models. Founded in 2015, it became the company that put generative AI in front of a mainstream audience, and it is now one of the most valuable private companies in the world.
Key points
- Founded in 2015 by Sam Altman, Greg Brockman, Ilya Sutskever, and others, headquartered in San Francisco.
- Best known for ChatGPT, used by more than 900 million people weekly, plus the GPT API and Codex.
- Restructured in 2025 into OpenAI Group PBC, controlled by the nonprofit OpenAI Foundation.
- Backed heavily by Microsoft, with strategic capital from Nvidia, Amazon, and SoftBank.
What it builds
OpenAI’s flagship product is ChatGPT, a consumer and enterprise assistant available across free and paid tiers. Around it sits a developer platform: the GPT API, which serves models on a usage basis, and Codex, a coding tool for software work. Enterprise now makes up a large and growing share of revenue, alongside consumer subscriptions.
How it is structured
OpenAI began as a nonprofit research lab and later added a capped-profit arm to attract capital. In 2025 it completed a recapitalization that created OpenAI Group PBC, a public benefit corporation controlled by the nonprofit OpenAI Foundation. The Foundation holds equity in the for-profit and retains control, a structure that shapes how any future public listing would work.
Why investors watch it
OpenAI is private, so there is no ticker to buy. It filed a confidential draft S-1 in June 2026, an early step toward a possible IPO that could be one of the largest in history. Until shares list, the closest public exposure is through its backers, especially Microsoft. For the full picture, see the valuation, business, and how to invest pages.