OpenAI's ChatGPT has crossed 1 billion global monthly active app users, becoming the fastest application ever to reach that milestone, according to estimates from market intelligence firm Sensor Tower.
The record highlights the accelerating adoption of generative AI and intensifies the competitive race between OpenAI and Anthropic for dominance in the rapidly expanding market. Both companies are preparing for initial public offerings in the coming weeks.
"ChatGPT's trajectory reflects the mainstreaming of AI assistants, but the competitive window is narrowing as rivals like Claude gain traction," said Alex Nguyen, enterprise AI analyst at Edgen. "The next battleground will be retaining users, not just acquiring them."
ChatGPT reached 1 billion monthly active users in May, roughly three years after its launch, surpassing the adoption pace set by Google Maps, TikTok, Instagram and YouTube, Sensor Tower said. The firm's data showed that US ChatGPT users who installed Anthropic's Claude app in the first quarter of 2026 spent 5 percent less time on ChatGPT one month after installation, compared with their average usage in the prior eight months.
Anthropic confidentially filed for a US initial public offering on June 1, while Reuters has reported that OpenAI is also preparing to file for an IPO in the coming weeks. As of the second quarter to date, Claude had 56 million global monthly active app users, while its year-over-year MAU growth of about 640 percent significantly outpaced ChatGPT's 62 percent growth, according to Sensor Tower.
The user growth milestone underscores the scale of the AI market opportunity but also raises questions about retention and monetization. ChatGPT's 1 billion user base represents a massive addressable audience for potential advertising or subscription revenue, yet the faster growth rate of a smaller rival suggests the competitive dynamics remain fluid. OpenAI's path to an IPO will depend partly on its ability to demonstrate sustained engagement and a clear revenue model beyond its current subscription tiers.
This article is for informational purposes only and does not constitute investment advice.