Analytics firm Sensor Tower's "2026 AI Status Report" reveals that as of the end of May 2026, ChatGPT's global market share has fallen to 46.4% — the first time it has dipped below the 50% threshold since launch. Google's Gemini and Anthropic's Claude are eating into ChatGPT's user base, with their shares climbing to 27.7% and 10.3%, respectively.
According to the report, brand values and trust directly drive user attrition. OpenAI's partnership with the US Department of Defense (DoD) in February 2026 triggered a 295% surge in ChatGPT uninstalls. Meanwhile, platforms are accelerating monetization. OpenAI began testing ads in ChatGPT in February 2026, and by May, 17% of daily active users were exposed to ads, with software and shopping as the biggest advertiser categories.
In terms of monetization and channels, Claude tops the industry with a 13% paid conversion rate, thanks to its sticky productivity scenarios. And as ChatGPT deepens its shopping referrals, referral traffic to retailers like Walmart and Costco has grown significantly, while Amazon — which has blocked ChatGPT's web crawler — sees stagnant referral traffic.