ChatGPT’s market share has fallen below 50% – and consumers are still willing to switch allegiance.
ChatGPT’s market share has fallen from 80% in May 2023, to just below 50% in May of 2026.
While ChatGPT is the fastest app to reach one billion monthly active mobile users, taking just three years to hit the milestone, its market dominance is slipping.
As of this month, Google’s Gemini is the closest competitor, with a 27.7% market share, followed by Claude, which is rapidly growing with 10.3%, according to Sensor Tower’s State of AI report 2026.
Consumers are willing to switch chatbots, with allegiances not established enough to keep users on one specific platform. For example, there is a distinct shift in users away from OpenAI’s ChatGPT towards Anthropic’s Claude in the months following February 2025, which is when OpenAI announced a partnership with the US Department of Defence.
It was after this agreement that ChatGPT’s share dipped below 50% for the first time.
ChatGPT’s worldwide audience market share went from over 85% in April 2023, to 45% in May 2026, illustrating the volatility in the LLM market and the willingness from customers to experiment with different platforms as they develop and evolve.
Anthropic, in contrast, publicly declined a partnership with the Pentagon. While ChatGPT uninstalls were peaking in the US at roughly 200% above the app’s average, Anthropic was offering an alternative, and recorded more daily downloads than ChatGPT from March 1-5, and has led every day since.
This highlights to marketers the importance of diversifying their LLM investment and of following audience trends to get ahead of any market shifts owing to policy, regulatory, or consumer changes.
The AI app market itself is continuing to expand, although it has slowed down from the rapid acceleration seen in 2025. Sensor Tower predicts global downloads to reach 2.3 billion (a 7% increase half-over-half (HoH) – a significant deceleration from the 26% growth the market enjoyed in H2 of 2025.
In-app purchases
Significantly, global in-app purchase (IAP) revenue from AI apps is expected to rise 36% HoH, and is set to reach over $4bn in H1 of 2026.
This is notable since AI firms have found it notoriously difficult to turn a profit, with OpenAI’s ad business to fall short of revenue forecast by 90% – forcing the tech platforms to consider other areas for monetisation.
AI is shifting towards a more professional use-case with businesses expanding their usage and the number of users paying for premium features and subscriptions seeing significant growth. Claude has positioned itself as a tool for research and professional workflows, and as such has seen average monthly revenue per user (ARPU) grow from less than $0.50 in September 2025 to $2.76 in May 2026.
This does pose a potential challenge (and opportunity) for advertisers who may be looking to integrate their products into ChatGPT and other chatbots. As it stands, ads within the services are primarily retail-focused – but a business-forward shift might mean that B2B advertising is more successful.
