OpenAI’s ChatGPT’s market share fell below 50% for the first time since it was launched more than three and a half years ago. This comes as users are increasingly migrating to other chatbots like Google’s Gemini, Anthropic’s Claude, and xAI’s Grok, according to analytics firm Sensor Tower’s State of AI Report for 2026.
ChatGPT has shown impressive growth ever since it was launched. Sensor Tower’s report mentioned that the chatbot had become the fastest app to reach one billion monthly users. OpenAI also counts weekly active users, and it last reported 900 million of them in February. It remains the most popular AI assistant worldwide with over 1.1 billion monthly users, followed by Gemini with 662 million and Claude with 245 million.
ChatGPT had 50% of the market share till January, however that fell to 46% by May’s end because of the rise of Gemini (27.7%) and Claude (10.3%). Other assistants including Grok, Perplexity, DeepSeek, and Meta AI have less than 5% market share.
READ: ChatGPT reaches 1 billion monthly users, becoming fastest app to hit milestone (June 3, 2026)
Sensor Tower’s State of AI Report also found that users are increasingly willing to switch between assistants. Users are often motivated to switch because of specific events. For instance, OpenAI’s $200 million contract with the U.S. Department of Defense led to a surge in ChatGPT uninstalls. According to TechCrunch, while Gemini gained a lot of momentum due to its integration with Google’s broader ecosystem of tools, Anthropic’s Claude gained a strong reputation for productivity use cases and is closing in on ChatGPT’s user retention rate.
Sensor Tower said that in the first half of 2026, consumers are on pace to download nearly 2.3 billion AI apps and spend more than $4.2 billion on them. That marks a sharp increase from the $1.83 billion spent in the first half of 2025, suggesting the industry is increasingly focused on monetization rather than growth alone. However, both download and spend growth rates have decelerated, indicating that the market may be maturing even as absolute numbers rise.
READ: OpenAI joins AI ‘superapp’ race: What it means for ChatGPT users (March 20, 2026)
Asia first recorded the first download decline of 3.3% in Q1 2026, driven by dips in China and India. While Asia leads in global downloads, the region trails North America and Europe when it comes to in-app spending. This split matters to companies deciding where to invest in premium features and monetization.
In the U.S., users are gravitating toward AI assistants for productivity tasks and spending more on premium features. Claude in particular stands out as 13% of Anthropic’s users paying for a subscription plan.
Sensor Tower estimates that the hours spent on AI apps will have increased from 17.2 billion hours in first half of 2025 to roughly 36 billion hours in the same period of 2026. The top three assistants command 89% time spent on AI assistant apps. However, adjacent categories like AI companions or AI content generation apps remain fragmented and wide open to competition.