Sam Altman has told staff at OpenAI that ChatGPT is growing again, with usage increasing by more than 10% each month.
The message, shared internally and seen by CNBC, said the company is also getting ready to release “an updated Chat model” this week.
ChatGPT now has more than 800 million people using it every week and competition is getting tougher.
Google’s Gemini app passed 750 million monthly users at the end of last year, while Anthropic has gained ground, especially among software developers.
The pressure is being felt most in coding tools. In his note to staff, Altman said OpenAI’s own coding product, Codex, had grown by about 50% in just one week.
Codex goes head-to-head with Anthropic’s Claude Code, which has seen fast uptake over the past year.
OpenAI released a new version of Codex, called GPT-5.3-Codex, last week. Altman described the recent momentum as “insane” and added: “This was a great week.”
The company’s push comes after a period of concern about slowing growth. In December, OpenAI shifted staff and resources to improve ChatGPT as competitors closed in, both in growth and other areas.
Since then, the focus has been on keeping users engaged while expanding paid and business services.
OpenAI is also moving ahead with plans to show adverts inside ChatGPT for some users in the United States. The company has said the ads will be clearly marked, appear at the bottom of responses and will not affect what the chatbot says.
Behind the scenes, Altman and finance chief Sarah Friar have been briefing investors on OpenAI’s performance as the company seeks to complete a large funding round.
CNBC has reported that discussions involve several major technology firms and could be finalised in stages. The figures and structure are still under discussion and may change.
For now, the message to ChatGPT staff was that growth in usage is here again, new products are rolling out, and OpenAI believes it has regained momentum in a crowded market.
