OpenAI Tracks User Activity Across Third-Party Sites via ChatGPT Cookie

By Constantine von Hoffman · MarTech · 2026-09-23

OpenAI Tracks User Activity Across Third-Party Sites via ChatGPT Cookie

MarTech reports that an independent researcher identified a persistent cookie, labeled __obi, that allows OpenAI to follow ChatGPT users as they visit other websites. This mechanism enables the company to link initial chatbot interactions with later conversions on external pages

MarTech reports that an independent researcher identified a persistent cookie, labeled __obi, that allows OpenAI to follow ChatGPT users as they visit other websites. This mechanism enables the company to link initial chatbot interactions with later conversions on external pages