US Website Traffic Shifts Amid GA4 Mandate and AI Overviews

Over the past year, U.S. website traffic patterns have undergone notable shifts, influenced by the mandatory transition to Google Analytics 4 (GA4) on July 1, 2023, and the subsequent rollout of AI Overviews by Google in May 2024. This period marked the cessation of new data processing for standard Universal Analytics properties, removing a consistent measurement baseline just as search traffic dynamics began to evolve. Data from Semrush Traffic Analytics, analyzed as of July 2026 and compared to the previous year, indicates that while the top-tier websites have maintained their positions, their traffic volumes have seen substantial changes. Google remains the leading website in the U.S., attracting 25.3 billion monthly visits, an increase of 10.72% year-over-year. YouTube secured the second position with 10.3 billion monthly visits, experiencing a significant surge of 36.6% compared to the prior year. Reddit maintained its third-place ranking with 2.61 billion visits. Collectively, Google and YouTube now command a substantial portion of online attention, with the top three sites alone accounting for 54.3% of the traffic within the top 10. This indicates a tightening concentration of traffic at the very top of the web, rather than a decentralization, despite the ongoing integration of AI into search functionalities. The overall growth in website visits across the top 150 U.S. sites was more modest, rising by 6.1% year-over-year. The top 10 sites collectively accounted for 68.6% of all traffic, a figure nearly identical to the 68.8% recorded a year earlier, further underscoring the persistent concentration. The data suggests that the web's traffic landscape is becoming more consolidated, with established giants like Google and YouTube experiencing significant growth, and new entities emerging within this concentrated ecosystem. The shift to GA4, while disruptive to historical data comparison, has coincided with these evolving traffic dynamics. The AI Overviews feature, which began its U.S. rollout in May 2024, is poised to further influence search result visibility and, consequently, website traffic patterns in the coming periods. The analysis highlights the critical importance for brands to understand their visibility within AI-generated search results and to monitor competitor performance in this evolving digital environment. The Semrush Traffic Analytics tool provides a granular view of these changes, enabling businesses to adapt their strategies in response to the shifting landscape of online engagement.