OpenAI is watching its AI crown slip as new Sensor Tower data reveals ChatGPT's user growth has dramatically slowed to just 6% over three months while Google's Gemini surged 30% in the same period. The shift signals the first real threat to ChatGPT's dominance in the AI chatbot wars, with market saturation potentially hitting the category leader.
The AI chatbot race just got a lot tighter. OpenAI's ChatGPT, which has dominated the space since its explosive launch, is showing clear signs of market maturation as its user growth drops to single digits while competitors accelerate past it.
New data from market intelligence firm Sensor Tower reveals ChatGPT's monthly active users grew just 6% from August to November 2025, reaching roughly 810 million users. That's a dramatic slowdown for an app that saw 180% year-over-year growth and suggests the AI pioneer may be hitting market saturation.
Meanwhile, Google's Gemini is capitalizing on ChatGPT's deceleration. The search giant's AI assistant saw its user base surge 30% during the same three-month period, largely fueled by the breakout success of its Nano Banana image generation model that launched in September. Gemini users are now spending 11 minutes daily in the app, more than double the time from March.
The competitive gap is narrowing fast. While ChatGPT maintains its lead with 55% of global monthly active users and 50% of mobile downloads, Gemini has gained three percentage points of market share over the past seven months. In a mirror image, ChatGPT lost three percentage points over the past four months alone.
Google has a structural advantage that's becoming increasingly apparent. The Sensor Tower report found that twice as many U.S. Android users engage with Gemini directly through the operating system compared to the standalone app. With Android dominating globally, this OS-level integration gives Gemini distribution ChatGPT can't match.
The pressure is showing at OpenAI. CEO Sam Altman recently issued a "code red" memo instructing staff to focus on improving personalization, reliability, and image generation - areas where competitors are gaining ground. The internal alarm reflects growing awareness that ChatGPT's first-mover advantage is eroding.
Other players are also eating into ChatGPT's dominance. Perplexity saw explosive 370% year-over-year growth, while Claude jumped 190%. Both represent triple-digit growth that's putting additional pressure on the category leader. ChatGPT's 85% download growth, while impressive in absolute terms, lagged the overall cohort's 110% average.
