ChatGPT Falls Below 50% Market Share for First Time

ChatGPT's dominance in the AI assistant market is slipping. More than three and a half years after its launch, OpenAI's chatbot has seen its market share fall below 50% for the first time, as users increasingly migrate to Google's Gemini, Anthropic's Claude, and xAI's Grok, according to Sensor Tower's State of AI Report for 2026More than three and a half years after ChatGPT's initial release, AI assistants are now used by millions of people worldwide, and the competitive landscape is changing fast. While OpenAI's chatbot is still the most popular assistant globally, its market share has dipped below 50% for the first time as users are migrating between different assistants like Google's Gemini, Anthropic's Claude, and xAI's Grok. 

ChatGPT remains the largest player by raw users, with over 1.1 billion monthly users compared to Gemini's 662 million and Claude's 245 millionThe chatbot still remains the most popular AI assistant worldwide with over 1.1 billion monthly users, followed by Gemini with 662 million and Claude with 245 million. But its share dropped from over 50% in January to 46.4% by May, as Gemini climbed to 27.7% and Claude to 10.3%Until January, ChatGPT commanded over 50% market share, but by May's end, it had fallen to 46.4% thanks to the rise of Gemini (27.7%) and Claude (10.3%). 

Notably, brand trust appears to influence switching behavior directly—OpenAI's February deal with the U.S. Department of Defense triggered a measurable spike in uninstallsOpenAI's deal with the U.S. Department of Defense (DoD) in February triggered a measurable spike in uninstalls — suggesting brand trust and values alignment matter to users, not just features. 

Monetization is accelerating industry-wide: users are projected to spend over $4.2 billion on AI apps in H1 2026, more than double the $1.83 billion spent in H1 2025people are on pace to download nearly 2.3 billion AI apps and spend over $4.2 billion on them, according to Sensor Tower estimates. That compares to $1.83 billion in spending in H1 2025. Claude leads on conversion specifically, with 13% of Anthropic's users paying for subscriptions—the highest rate in the fieldThirteen percent of Anthropic's users are paying for a subscription plan — a conversion rate that leads the field.

Analysis: This data signals a maturing market shifting from pure user-growth competition toward retention, monetization, and brand differentiation. ChatGPT's uninstall spike following its DoD deal suggests users are making values-based choices, not just feature comparisons—a dynamic that smaller, trust-focused competitors like Claude may be positioned to exploit, especially given its leading conversion rate despite a much smaller user base.