January 13, 2026 Fresh traffic and market-share data from Similarweb shows that ChatGPT, once the unchallenged default for consumer AI, has seen a sharp drop in usage over the past six weeks. Meanwhile, Google’s Gemini continues to close the gap and deepen user engagement.
According to the data, ChatGPT’s average daily visits fell by roughly 22 per cent between early December and early January. Its seven-day average slid from about 203 million daily visits to around 158 million by early January. Over the same period, Gemini maintained a steadier base, attracting between 55 million and 60 million daily visits.
That shift is now clearly visible in market share. As of January 2, 2026, ChatGPT accounted for about 64.5 per cent of global generative AI usage, down from roughly 68 per cent in December and far below the 86 per cent share it commanded a year earlier. Gemini, by contrast, has expanded rapidly, growing from just 5.7 per cent in January 2025 to approximately 21.5 per cent today.
While ChatGPT still leads by a wide margin, Similarweb’s analysis suggests its growth curve has flattened. Gemini appears to be drawing an increasing share of users directly from OpenAI’s platform. In early December, Similarweb estimates Gemini cannibalised around 31-33 per cent of ChatGPT’s traffic. By the end of the month, that figure had climbed to nearly 39-40 per cent.
The data also highlights a difference in how users interact with the two services. Gemini attracts fewer visitors overall, but those users tend to stay longer and explore more. Average session duration on Gemini is now about 7 minutes and 20 seconds, compared with 6 minutes and 32 seconds on ChatGPT. Page views per visit also skew higher, with Gemini averaging 4.3 pages per session versus 3.8 on ChatGPT.
Beyond the two market leaders, smaller platforms are also gaining incremental ground. Grok has moved past the 3% market share mark and is narrowing the gap with DeepSeek, which stands at roughly 3.7%. Perplexity and Claude remain steady at around 2% each, while Microsoft’s Copilot continues to lag at about 1.1%, showing little momentum over the past year.
The numbers point to a generative AI market that is rapidly maturing. ChatGPT remains the largest player by far and its user base remains vast. But other tools are coming for the near-total dominance it holds.
