OpenAI's artificial intelligence (AI) model ChatGPT's global market share has fallen below 50% for the first time. Analysts say users are dispersing to competing services such as Google Gemini and Anthropic Claude.
On the 16th, TechCrunch reported, citing market research firm Sensor Tower's "2026 AI status report," that ChatGPT's market share last month was tallied at 46.4%. ChatGPT maintained a share above 50% as recently as January this year, but as Gemini and Claude continued to gain, the 50% mark was broken.
During the same period, Gemini raised its share to 27.7%, and Claude to 10.3%. The individual shares of other AI assistant services such as Grok, Perplexity, DeepSeek, and Meta AI remained below 5%.
Still, ChatGPT's growth trajectory itself remains steep. Sensor Tower said this month that ChatGPT became the app to reach 1 billion monthly users the fastest. OpenAI also releases its own weekly active user figures, and as of February, weekly active users alone reached 900 million. As of May, Gemini and Claude had 662 million and 245 million monthly users, respectively.
Sensor Tower explained that users are increasingly inclined not to stay with a single AI service but to switch among multiple AI assistants. It said not only simple feature differences but also brand trust and values influence user movement. In fact, after OpenAI signed a contract with the Ministry of National Defense in the United States in February, there were more cases of people deleting the ChatGPT app.
The growth drivers differ by service. Gemini is rapidly expanding its user base by integrating with Google Search, Docs, email, and other existing service ecosystems. Claude, by contrast, is growing as it is recognized for strengths in productivity areas such as document writing, coding, and workflow automation.
Meanwhile, Sensor Tower estimated that time spent using AI apps will increase from 17.2 billion hours in the first half of 2025 to about 36 billion hours in the first half of 2026.