OpenAI’s ChatGPT, with 1.1 billion monthly users, saw its global market share drop to 46.4% in May as Google’s Gemini and Anthropic’s Claude gained ground. Sensor Tower data shows installs and spending on AI apps are up, but growth is slowing and users are switching assistants more often, driven by features, pricing and brand trust.

• ChatGPT's market share dropped from 50%+ in January to 46.4% by May as Gemini (27.7%) and Claude (10.3%) gained ground
• A spike in ChatGPT uninstalls after OpenAI's February defense deal suggests brand trust/values now drive user churn as much as features do
• AI app spending grew to $4.2 billion in H1 2026 (from $1.83 billion in H1 2025), but growth is slowing and Asia saw a 3.3% download decline in Q1
• ChatGPT's shopping referral links are boosting traffic to Target and Costco while Amazon blocks its crawlers, and Walmart's Spark assistant is closing in on Amazon's Rufus