ChatGPT is slipping. For the first time since its launch, OpenAI's chatbot has fallen below 50% market share, according to analytics firm Sensor Tower's latest State of AI Report.
The numbers are stark. ChatGPT held over 50% of the market until January 2026. By May, it had fallen to 46.4%.
Google's Gemini is advancing with 27.7% market share and 662 million monthly users, while Anthropic's Claude has reached 10.3% share and 245 million users. ChatGPT still has 1.1 billion monthly users, but the momentum has shifted.
A notable trigger for defections emerged in February, when OpenAI's deal with the U.S. Department of Defense prompted a measurable spike in uninstalls. The data suggests users weigh values alignment alongside capability.
Gemini's growth stems from integration into Google's product suite, while Claude is gaining ground on productivity features and retention rates approaching ChatGPT's. Grok, Perplexity, DeepSeek, and Meta AI each hold under 5% share.
The AI assistant market itself is expanding. Users are projected to download nearly 2.3 billion AI apps in the first half of 2026 and spend over $4.2 billion, nearly double last year's $1.83 billion. Growth is cooling, however, signalling market maturation.
Asia, the largest download region, recorded its first regional decline in Q1 2026, down 3.3%. Competition among providers is intensifying even as overall growth slows.
