ChatGPT Hits 1 Billion Users As Claude Gains Market Share

- ChatGPT reaches 1 billion monthly active users, setting new adoption record - Anthropic’s Claude rapidly gains downloads, users, and technical recognition On 2026-06-03, Sensor Tower reported that ChatGPT hit 1 billion global monthly active users in May 2026. This set a new record as the fastest application ever to reach this milestone and surpassed the historical growth trajectories of apps such as Google Maps, TikTok, Instagram, and YouTube. ChatGPT’s user growth had slowed in late 2025, with just a 6% increase over a three-month period as it neared saturation; however, engagement rebounded in early 2026. On 2026-06-02, Reuters reported that ChatGPT remains the leading AI chatbot by user base. However, its global share of AI app downloads declined from 67% in Q2 2025 to 47% in Q2 2026. During the same period, Reuters reported that Anthropic’s Claude increased its share of downloads from 1% to 14%, and its monthly active users rose to 56 million, representing a 627% year-on-year increase compared to ChatGPT’s 67% growth. As a result, most users now appear to divide their time between both platforms. On 2026-06-02, Reuters further reported that Anthropic had confidentially filed for a U.S. IPO on 2026-06-01. In addition, Al Jazeera reported on 2026-05-29 that Anthropic’s $65 billion funding round pushed its valuation to $965 billion, eclipsing OpenAI’s $852 billion valuation in March 2026. Meanwhile, prediction market data from Polymarket on 2026-06-03 indicated a 74% probability that Anthropic would list before OpenAI and an 84% probability that it would own the leading AI model by the end of June 2026. On 2026-05-31, OpenTools reported that Claude’s latest model surpassed OpenAI’s GPT-5.5 on 12 major benchmarks, including advanced knowledge work and long-context tasks. These technical assessments further boosted Claude’s momentum and reinforced perceptions of intensifying competition in frontier AI models. Overall, market data affirms ChatGPT’s record-setting growth as of May 2026, while Anthropic’s Claude, driven by surging user numbers, large-scale investment, and strong technical performance, signals an increasingly competitive and dynamic AI landscape.