OpenAI's ChatGPT global market share has fallen below 50 percent for the first time, TechCrunch reported on June 16, citing Sensor Tower's "2026 AI Status Report."

ChatGPT's share stayed above 50 percent through January but fell to 46.4 percent as of end-May, the report said. Over the same period, Gemini rose to 27.7 percent and Claude climbed to 10.3 percent. The remaining assistants, including Grok, Perplexity, DeepSeek and Meta AI, each have less than 5 percent share.

ChatGPT still has 1.1 billion monthly users, making it the world's most-used AI assistant. Google's Gemini follows with 662 million, and Anthropic's Claude has 245 million.

ChatGPT became the fastest app to surpass 1 billion monthly users, 3.5 years after launch. By weekly active users, ChatGPT users exceeded 900 million in February.

Sensor Tower assessed that users are becoming increasingly active in switching among assistants. It cited a case in which ChatGPT deletions increased noticeably after OpenAI and the U.S. Department of Defense signed a contract in February, and said brand trust and whether values align, as well as features, affect user choice.