OpenAIs ChatGPT may be the worlds most popular chatbot app. But rival services are gaining, according to data from analytics firms Similarweb and Sensor Tower.SimilarWeb, which estimates traffic to websites including chatbot web apps, has recorded healthy recent upticks in usage across bots like Googles Gemini and Microsofts OpenAI-powered Copilot. Geminis web traffic grew to 10.9 million average daily visits worldwide in March, up 7.4% month-over-month, while daily visits to Copilot increased to 2.4 million up 2.1% from February.Similarweb reports that Anthropics Claude reached 3.3 million average daily visits in March, and Chinese AI lab DeepSeeks chatbot eclipsed 16.5 million visits that same month. Meanwhile, xAIs Grok, which only gained a web app several months ago, averaged the same number of daily web visits as DeepSeeks chatbot: 16.5 million.The numbers pale in comparison to ChatGPT, which surged past 500 million weekly active users in late March. Yet David Carr, editor at Similarweb, noted that theres fierce competition for the No. 2 chatbot spot.[F]or March, DeepSeek is in second place, despite seeing traffic drop 25% from where it was in February, based on daily visits, Carr told TechCrunch. Chinas DeepSeek came out of nowhere in January, but the AI platform with the greatest momentum at the moment is Grok from Elon Musks xAI, with traffic up nearly 800% month-over-month.AI companies mobile chatbot apps have been growing their user bases, too, perhaps fueled by recent AI model releases.According to metrics from app data analysis company Sensor Tower, the Claude app saw a 21% week-over-week increase in weekly active users during the week of February 24, when Anthropic released its latest flagship AI model Claude 3.7 Sonnet. Two weeks prior, shortly after Google made its Gemini 2.0 Flash model generally available, the number of Gemini app weekly active users grew by 42%. Abraham Yousef, senior insights analyst at Sensor Tower, attributed the rising tides not only to new models, but new capabilities, as well. Just this past month, Google brought a canvas feature to Gemini that lets users preview the output of coding projects, and Anthropic has steadily added tools to its Claude client.The rollout of popular new AI models, heightened consumer interest in the space, the introduction of various new features and functions, and the growing number of unique use cases has propelled user growth for AI chatbot apps, Yousef told TechCrunch. But OpenAI probably isnt panicking yet. Yousef pointed out that ChatGPT had 10x mobile app weekly active users compared to Gemini and Claude combined as of March.