The record, reported by market analytics firm Sensor Tower, comes amid growing competition between Anthropic and OpenAI as both companies compete for leadership in the rapidly expanding artificial intelligence market.
According to Sensor Tower, ChatGPT reached 1 billion monthly active users in May, approximately three years after its launch, outpacing the growth rates achieved by applications such as Google Maps, TikTok, Instagram, and YouTube.
The company also reported that U.S. users who downloaded Anthropic’s Claude app during the first quarter of 2026 spent 5% less time on ChatGPT one month after downloading Claude compared to their average usage during the previous eight months.