ChatGPT is still dominant, but dominance is different from exclusivity
Similarweb's July 2026 analysis places ChatGPT at approximately 53% of worldwide generative AI website traffic by May 2026, compared with roughly 76% in June 2025. Over the same period, Gemini rose from below 9% to approximately 27 to 28%, while Claude increased from around 2% to almost 9%. Together, those changes have transformed what was once an overwhelmingly ChatGPT-led category into a much more distributed market.
It is important not to interpret that as evidence that ChatGPT itself is collapsing. Similarweb reports that ChatGPT's absolute website visits remained roughly flat while the overall generative AI category expanded around it. Average monthly visits across generative AI platforms increased by 70% year on year to approximately 9.5 billion between June 2025 and May 2026. ChatGPT owns a smaller percentage of a substantially larger market.
Gemini has become too large for marketers to treat as secondary
The most significant change is arguably Gemini rather than ChatGPT. Moving from less than one tenth of generative AI website traffic to more than one quarter in approximately twelve months means a substantial audience now conducts AI-assisted discovery outside ChatGPT. Gemini's position within Google's wider ecosystem also gives it multiple routes through which users can encounter AI-generated information.
For marketers, this creates a simple problem. A brand can perform extremely well when a potential customer asks ChatGPT for a recommendation and still be missing when the equivalent question is asked elsewhere. If a significant proportion of the addressable audience has moved towards Gemini, knowing only what ChatGPT says about the business provides an increasingly incomplete view of AI visibility.