OpenAI’s rivals are cutting into ChatGPT’s lead. The top chatbot’s market share fell from 69.1% to 45.3% between January 2025 and January 2026 among daily U.S. users of its mobile app. Gemini, in the same time period, rose from 14.7% to 25.1% and Grok rose from 1.6% to 15.2%.The data, obtained by Big Technology from mobile insights firm Apptopia, indicates the chatbot race has tightened meaningfully over the past year with Google’s surge showing up in the numbers. Overall, the chatbot market inc...