OpenAI is an American artificial intelligence (AI) research organization headquartered in San Francisco. It develops generative AI models, particularly the generative pre-trained transformer (GPT) series of large language models (LLMs). Its release of ChatGPT in November 2022 has been credited with catalyzing the AI boom; as of 2026 ChatGPT is the fifth-most-visited website globally. OpenAI also releases Codex, an AI coding agent, and the GPT Image models.