ChatGPT still pulls more web traffic than any single rival chatbot, but it no longer owns the category the way it did two years ago. Similarweb’s 2026 Generative AI Landscape report puts ChatGPT’s slice of tracked chatbot web visits at just above 50 percent by this past May, down from over 80 percent in late 2024, with Gemini, Perplexity, DeepSeek and Claude splitting up most of what it lost. The figure that matters for GEO planning is not the drop by itself. It is what sits underneath the drop: the whole category kept expanding while ChatGPT’s portion of it got smaller.
Similarweb’s twelve-month window running through May 2026 shows average monthly visits across generative AI platforms climbing to 9.5 billion, a 70 percent jump from the 5.6 billion recorded the prior year. Unique monthly visitors grew 57 percent over the same stretch, reaching 655 million from 418 million. Set against that expansion, ChatGPT’s shrinking share describes a product still adding real users while ceding relative ground to a wider field. Claude’s piece of that same chatbot pool roughly tripled across the period, and Similarweb’s June reading had ChatGPT down to 52.7 percent.
Monetization moved the other direction. Similarweb found ads inside 26 percent of US desktop ChatGPT sessions in June 2026, a level the firm describes as evidence that advertising is now a fixture of the product rather than a test. PPC Land, which broke out these figures on July 22, treats that ad-penetration number and the share erosion as the two facts that define the chatbot market’s current shape.
The overlap finding deserves the most attention from GEO teams. Similarweb counted roughly 494 million people who used ChatGPT worldwide across a recent three-month stretch, and 95 percent of them, about 461 million, also searched on Google in that same window. The ratio has held near that level since last September. A GEO program built around ChatGPT citations alone is chasing a channel that, for nearly all of its own audience, functions as a side stop rather than a substitute for search.
Some skepticism is warranted. Similarweb is a single measurement vendor pulling from web-visit and panel data that misses a good share of activity inside native mobile apps, which is where several of these products are growing fastest. The report’s own download numbers do not agree with each other: one page puts total downloads at 2.7 billion with 134 percent annual growth, while a chart later in the document puts the same figure at 4.4 billion against a prior-year base of 2.8 billion, a gain closer to 58 percent. Similarweb never squares those two counts against one another.
That inconsistency does not undercut the chatbot-share trend, which tracks a single metric, visits, applied consistently to the same platform set month by month. It does mean the download and app-adoption numbers in this report should carry a caveat that the visit-share chart does not need.
For a GEO team, the sensible response is a reweighting, not an exit from ChatGPT. Citation tracking, structured answers and clear entity signals still belong there because it remains the largest individual chatbot by traffic. But a program with no comparable tracking on Gemini and Claude, where share and app usage are both growing fastest, is measuring an ever-smaller fraction of the market it claims to serve. Shift monitoring hours and testing budget toward whichever two or three surfaces are gaining share fastest this quarter, sized to their real traffic, not to which one launched first.
Given how much of ChatGPT’s own audience never leaves Google behind, the safer long-term structure treats classic Google visibility as the shared foundation under every chatbot surface, with platform-specific GEO work layered on top of it rather than standing in for it.
PPC Land (Luis Rijo) reported these figures on July 22, 2026, citing Similarweb’s 2026 Generative AI Landscape report as the data source.
