ChatGPT Loses Majority Market Share While Setting User Growth Record

ChatGPT's share of the AI assistant market fell below 50% in June 2026, even as the platform reached 1.1 billion monthly active users—the fastest adoption trajectory of any application. Google Gemini's 662 million users compressed OpenAI's majority. The shift marks the end of single-vendor dominance; the market has expanded faster than any one player's growth rate, leaving room for structural competitors leveraging distribution advantages like Android defaults and Search integration.