ChatGPT hit 664 million mobile daily active users in September, up 7% from August and 69% year over year, according to Sensor Tower data cited by Bank of America analyst Justin Post. OpenAI said on September 29 that ChatGPT has 1.2 billion weekly users.

Google's Gemini reached 151 million mobile daily users, up 11% month over month and up 321% from last year. The Gemini app passed 1 billion monthly users in August.

Meta's new Muse agent app climbed to 1.96 million mobile daily users within weeks of its September 8 launch. For comparison, xAI's Grok sits at 2 million mobile daily users and Meta's own Meta AI app stands at 6 million.

Bank of America frames the numbers as part of a consumer shift away from plain chat toward autonomous, agentic systems that take actions on users' behalf.