OpenAI CEO Sam Altman told employees that the startup's artificial intelligence chatbot, ChatGPT, was back to exceeding 10% monthly growth, CNBC reported Monday.

The startup, which has more than 800 million weekly active users, is also preparing to launch "an updated Chat model" this week, the report said, citing an internal Slack message from Altman.

OpenAI did not immediately respond to a Reuters request for comment. Reuters could not independently verify the report.

AI startups, including Microsoft-backed OpenAI and Anthropic, are stepping up competition to gain new customers and market share.

Google Gemini app exceeded 750 million monthly active users at the end of the December quarter.

Anthropic is seen as a disrupter in the software industry, as software developers have embraced its AI for coding.

It is making a push for business deals with products like Claude Cowork, which executes computer tasks for white-collar workers.

Altman said OpenAI's coding product, Codex, grew about 50% from a week ago.

Codex competes directly with Anthropic's computer programming tool Claude Code, the CNBC report said.

Last week, OpenAI launched a new coding model called GPT-5.3-Codex.

OpenAI has said it would start showing ads in ChatGPT to some U.S. users, as it ramps up efforts to generate revenue from the AI chatbot to fund the high costs of developing the technology.