New data from Similarweb reveals massive spikes in traffic and app downloads, while the user base expands to include older generations.
According to a recent Similarweb analysis, generative AI has moved beyond mere curiosity to become an "Internet backbone" - a fundamental layer of web infrastructure.
In September 2025 alone, AI services racked up roughly seven billion monthly web visits, rivaling the traffic of major social networks. That represents a 76 percent jump compared to the previous year. Mobile growth is even starker: sessions in Gen AI apps increased fivefold, and app downloads surged 778 percent.
ChatGPT dominates global AI traffic
ChatGPT remains the primary driver of this expansion. OpenAI’s platform grew from about 19 million monthly visits in 2022 to roughly 5.9 billion by September 2025. This places the site among the world's five most visited websites, putting it in the same league as Instagram, which saw 6.5 billion visits in September 2025.
Despite rising competition from Gemini, Claude, and Perplexity, ChatGPT still commands nearly 80 percent of global Gen AI visits.
Search and chatbots are being used side by side
Similarweb's data suggests chatbots aren't replacing traditional search just yet. Of the 462 million people who visited ChatGPT, 95 percent also used Google. The 441 million overlapping users suggest people switch between conversational AI and search engines depending on the task.
ChatGPT also sees significantly higher engagement. In the U.S., 41.3 million people use the mobile app, with 33 percent opening it daily. By comparison, Perplexity (3.4 million MAU) and Microsoft Copilot (3.1 million MAU) see only 5 to 17 percent daily usage, indicating more sporadic habits.
Older demographics are adopting AI faster
Demographics are shifting as well. While 18 to 34-year-olds remain the largest cohort with 1.9 billion users (53 percent), older groups are adopting the technology fastest. Users aged 45 and over now make up nearly 30 percent of all visitors.
AI integration into existing ecosystems is also expanding. Google's "AI Mode" was the fastest Gen AI feature to reach 100 million visits in the U.S., driven by the company's massive reach. However, the numbers suggest usage remains experimental: more than half of users interacted with the feature on just a single day over a two-month period.
