Sensor Tower: ChatGPT's market share fell to 46.4% by 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
This is the latest in a run of audience-measurement reports showing ChatGPT’s lead narrowing. Earlier Apptopia data likewise put its US share materially lower over the prior year, while Gemini gained; Sensor Tower had also reported faster Gemini monthly-active-user growth than ChatGPT in late 2025.
The new reading broadens that competitive picture: Gemini and Claude now account for meaningful shares alongside ChatGPT, while Grok, Meta AI, and other assistants remain individually below 5%. It matters because the category is moving from a single clear consumer default toward a contested top tier.
First-order effects
- ChatGPT remains the largest assistant in Sensor Tower’s measure at 46.4%, but it no longer commands a majority share; Gemini at 27.7% and Claude at 10.3% are the immediate beneficiaries of a more divided market.
- The reported shares strengthen Gemini’s and Claude’s position in user acquisition and product positioning, while increasing the pressure on ChatGPT to defend engagement and retention rather than rely on category leadership alone.
Second-order effects
- Competition for distribution, product differentiation, and user loyalty should intensify among the three leaders, as gains by Gemini or Claude now have a more visible effect on ChatGPT’s relative position.
- Smaller assistants face a tougher route to scale: with each remaining below 5%, they must either find distinct use cases or overcome the growing concentration of attention among the leading products.
Third-order effects
- If successive measurements continue to show convergence, consumer AI assistants may settle into a multi-platform market in which leadership is contested by several products rather than locked in by the category’s first breakout app.
- That shift would make sustained engagement—not just initial adoption—the key competitive metric; the related coverage already points to differing growth and per-visit usage patterns among the leaders.
The trend: Consumer AI assistants are evolving from ChatGPT-led adoption into a more competitive, multi-player market where rivals are converting visibility into durable share gains.