OpenAI COO says ChatGPT recently crossed 400M WAU

OpenAI COO Brad Lightcap says the startup hit 400M weekly active users in February 2025, up 33% from 300M in December 2024, and 2M paying enterprise customers. In a post on X, the platform formerly known as Twitter, Lightcap said: “chatgpt recently crossed 400M WAU, we feel very fortunate to serve 5% of the world every week 2M+ business users now use chatgpt at work, and reasoning model API use is up 5x since o3 mini launch we’ll bring GPT-4.5 and GPT-5 to chat and the API soon, with unlimited GPT-5 for free users (plus and users can run at even higher intelligence) GPT-5 will unify our GPT and o-series models into a single powerful model — we think even low-taste testers will love it more agent capabilities coming this year as well, and a few other things.”