On September 29, OpenAI announced in its DevDay 2026 keynote that ChatGPT now has more than 1.2 billion weekly active users; the official recap page confirms "our collective 1.2B weekly users." In July, OpenAI's figure was 1 billion — 200 million more people now open ChatGPT every week, just two months later.
Three Numbers: 1.2 Billion, 35 Million, 2.5 Million
- 1.2 billion: ChatGPT weekly active users, up from 1 billion in July.
- 35 million: weekly users of ChatGPT Work and Codex — AI is accelerating into work scenarios.
- 2.5 million: businesses using OpenAI products.
The Money: Annualized Revenue Nearing $70 Billion
Beyond user scale, the revenue curve is steeper. Reports put OpenAI's annualized revenue at nearly $70 billion, up more than 70% since the start of the third quarter, with enterprise revenue more than doubling. Anthropic's annualized rate reportedly passed $65 billion in July, and the price war between the two in the enterprise market continues — which is exactly the backdrop for GPT-6.1 Sol launching at one-fifth the price, and for OpenAI raising a new round at a roughly $1.4 trillion valuation.
Where Growth Comes From: Work Scenarios Are Becoming the Second Curve
The notable structural shift is in user composition: 35 million weekly users of ChatGPT Work and Codex means growth no longer comes from the chat box alone. The always-on agent dots, Codex cloud environments, and the ChatGPT Space team workspace announced at the same DevDay all point one way — turning AI from a "Q&A tool" into a "work environment." Once 2.5 million businesses put OpenAI products into their workflows, subscription and API revenue gain a deeper moat than consumer memberships.
The worries are equally real: data center bills are the other side of this growth. Every additional 200 million users pushes inference costs up a level; with the price war pressing unit prices down, OpenAI has to amortize costs over ever-greater scale. 1.2 billion is a milestone — and the opening question of an exam on whether growth can outrun cost.
