ChatGPT Market Share Falls Below 50% for the First Time as AI Competition Intensifies

ChatGPT's share of the AI assistant market has dropped below 50% for the first time since its launch, despite remaining the world's most widely used AI assistant, according to Sensor Tower's State of AI Report 2026.

The report highlights a significant shift in the AI assistant landscape, driven by growing competition from rivals such as Google Gemini and Claude, resulting in a redistribution of users across major platforms.

ChatGPT continues to lead the market with more than 1.1 billion monthly active users. Gemini ranks second with approximately 662 million users, followed by Claude with around 245 million users.

According to the report, ChatGPT's market share declined from above 50% in January to 46.4% by the end of May 2026. Meanwhile, Gemini expanded its share to 27.7%, while Claude reached 10.3%.

Sensor Tower noted that AI users are increasingly willing to switch between platforms, with factors such as trust, company values and policy decisions influencing user behavior alongside technical performance. Several high-profile controversies also contributed to spikes in app deletions and shifting engagement trends.

The report attributes Gemini's growth to its deep integration across Google's ecosystem, while Claude strengthened its position in workplace and productivity environments and achieved the highest conversion rate to paid subscriptions among leading competitors.

Sensor Tower forecasts that AI applications will record 2.3 billion downloads during the first half of 2026, with global consumer spending expected to exceed $4.2 billion.

User engagement has also surged, with total time spent in AI applications reaching nearly 36 billion hours in the first half of 2026, up from 17.2 billion hours a year earlier. The three leading platforms collectively accounted for roughly 89% of total usage time.

Shopping Features and Advertising Expansion

The report also notes that several AI platforms, led by ChatGPT, have begun testing in-app advertising while expanding shopping-related features. The move has increased referral traffic to major e-commerce platforms, signaling a new phase for the industry focused on monetization and long-term sustainability alongside user growth.