Key facts
- OpenAI's ChatGPT app has surpassed 1 billion global monthly active users.
- ChatGPT is the fastest app to reach this milestone, achieving it in approximately three years.
- Anthropic's Claude app is showing faster year-over-year monthly active user growth.
- Both OpenAI and Anthropic are preparing for IPOs.
OpenAI's ChatGPT app has achieved a significant milestone, surpassing 1 billion global monthly active users. Sensor Tower estimates this makes it the fastest app ever to reach such a user base, achieving the figure in approximately three years. This record comes amid growing competition between OpenAI and Anthropic for dominance in the rapidly expanding artificial intelligence market. While ChatGPT reached 1 billion users fastest, Anthropic's Claude is demonstrating faster year-over-year monthly active user growth. U.S. users who installed Claude in Q1 2026 spent 5% less time on ChatGPT one month after installation compared to their average usage in the prior eight months. Both companies are reportedly preparing for IPOs, with Anthropic filing confidentially and OpenAI also preparing to file in the coming weeks. As of the second quarter to date, Claude had 56 million global monthly active app users, with its year-over-year MAU growth of about 640% significantly outpacing ChatGPT's 62% growth.