ChatGPT has surpassed 400 million weekly active users. "We feel very fortunate to serve 5 percent of the world every week," OpenAI COO Brad Lightcap said on X about the new audience stat. This figure is twice the weekly active user count reported by the company in August 2024, which was double the figure it posted in November 2023.

The latest milestone for the AI assistant comes after a huge uproar over new rival platform DeepSeek earlier in the year, which raised questions about whether the current crop of leading AI tools was about to be dethroned. OpenAI is on the verge of a move to simplify its ChatGPT offerings so that users won't have to select which reasoning model will respond to an input, and it will make its GPT-4.5 and GPT-5 models available soon in the chat and API clients. With GPT-5 being made available to OpenAI's free users, ChatGPT seems primed to continue expanding its audience base in the coming months.