Sensor Tower: ChatGPT's market share fell to 46.4% at the end of May, as Gemini rose to 27.7% and Claude to 10.3%; Grok, Meta AI, and others have less than 5%
More 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.
Context & Ripple Effects
Earlier coverage had already shown ChatGPT losing share in the US over 2025 while Gemini and Grok gained, even as ChatGPT retained a much larger active-user base. Sensor Tower also recorded Gemini growing far faster than ChatGPT in late 2025.
The latest figures extend that arc beyond a two-player contest: Gemini has become a substantial challenger and Claude has reached a meaningful share, while Grok, Meta AI, and other assistants remain fragmented.
First-order effects
- ChatGPT remains the largest measured assistant, but its 46.4% share means it no longer commands a majority of this market; Gemini at 27.7% and Claude at 10.3% have materially narrowed the gap.
- Gemini and Claude gain stronger evidence that users are distributing activity across multiple assistants rather than consolidating around the category’s early leader.
Second-order effects
- OpenAI faces greater pressure to defend engagement and differentiation, while Gemini and Claude can use their growing usage positions to compete more aggressively for consumer attention and developer mindshare.
- Smaller assistants face a tougher distribution challenge: with the leading three accounting for most measured share and each of Grok, Meta AI, and others below 5%, gains by one challenger do not yet translate into a broad long tail of viable competitors.
Third-order effects
- If successive measurements continue in this direction, consumer AI assistants may settle into a multi-platform market where share is contested on usage quality and retention rather than determined primarily by first-mover recognition.
- The gap between ChatGPT’s previously reported user scale and its declining share suggests that headline audience size will be an incomplete measure of competitive strength; relative engagement and switching will matter more.
The trend: Consumer AI is moving from an early ChatGPT-led market toward a more contested assistant landscape led by Gemini and Claude alongside the incumbent.