Gemini's Market Share Quadrupled: What It Means for GEO Strategy

Google's Gemini has nearly quadrupled its share of AI chatbot traffic in a year, climbing from around 5.7% to 21.5%, while ChatGPT's share fell from roughly 87% to 64.5%, according to Similarweb data reported by Search Engine Journal. That's the biggest reshuffle in the AI chatbot market since ChatGPT launched. For brands, it means a GEO strategy built entirely around ChatGPT is already out of date.

What changed?

Similarweb's January Global AI Tracker found that ChatGPT's tracked traffic share fell to 64.5% as Gemini rose to 21.5%, with writing and content generation sites falling over the same period, as reported by Search Engine Journal. The data measures visits at the domain level, so it captures people going directly to these tools on the web rather than through embedded features.

A separate breakdown of the same Similarweb tracker from Sitebard confirms the trend: Gemini's share grew from about 5.7% in early 2025 to roughly 21.5% by early 2026, nearly quadrupling in a year, while ChatGPT's share compressed from roughly 87% to around 64.5%.

Google's growth isn't just about people choosing Gemini directly. It's about distribution. Analysis from Techmagnate notes that Gemini's growth is driven less by model quality alone and more by distribution, since Google places it inside products billions already use, including Search, Android and Workspace, so people encounter Gemini without seeking it out. That built-in access is a structural advantage ChatGPT can't easily replicate.

The numbers vary slightly depending on the dataset and time window. A separate Similarweb cut covering a seven-app set, reported by Stackmatix, found ChatGPT accounted for approximately 54.7% of measured web visits among major AI chatbot platforms in April 2026 data, while Gemini captured roughly 27.4%, with the two platforms representing more than 80% of tracked traffic. Whichever slice you look at, the direction is the same. As Techmagnate puts it: "Both point the same way: ChatGPT down, Gemini up."

Gemini's reach through Search itself is enormous too. One estimate cited by Stackmatix suggests that through AI Overviews in Search, Gemini touches roughly 2 billion people monthly, giving Google unmatched total distribution. That's a separate channel from the standalone Gemini app or web visits, and it's arguably the bigger prize for brand visibility.

Why does this matter for your business?

If your GEO efforts have focused on ChatGPT because it's still the single largest platform, that instinct made sense a year ago. It's now riskier. A fifth of AI chatbot traffic is going through a system with a completely different retrieval and citation pipeline to OpenAI's, and it's the fastest-growing one in the market.

Google's own guidance is instructive here. As the company states in its developer documentation, the goal is reframing SEO best practices to understand what matters most to AI systems today, with the aim of improving a website's visibility in both generative AI search experiences and Google Search overall. Google also tells site owners directly to ignore the idea that they need to create new machine-readable files, AI text files, markup or Markdown to appear in Google Search, including its generative AI capabilities, since Google Search itself doesn't use them.

That matters for Gemini specifically because its answers inside Search and AI Overviews draw on the same underlying index and ranking systems as classic Google Search, unlike ChatGPT, Perplexity or Claude, which each run their own separate crawling and retrieval pipelines. In practice, solid, well-structured SEO fundamentals carry more weight for Gemini visibility than they do for other chatbots, while ChatGPT and Claude visibility depends more on being cited and discussed across third-party sites, forums and review pages.

The commercial stakes are becoming clearer too. Broader market analysis from Stackmatix notes that GenAI search ad spending in the US will roughly double between 2025 and 2026, reaching over $25 billion by 2029, an early signal that budgets are already shifting to chase this multi-platform audience rather than staying parked on legacy search alone.

What should you do now?

Stop treating "AI search visibility" as a single target. It's now at least four separate battlegrounds: ChatGPT, Gemini (via both the standalone app and Google's AI Overviews), Perplexity and Claude, each with different retrieval logic and different content that gets rewarded.

For Gemini specifically, the practical implication is simple: keep doing rigorous, classic SEO well. Clear structure, authoritative content, strong entity signals and technical crawlability still count, because Gemini's answers lean on Google's existing index rather than a separate crawl.

For ChatGPT, Claude and Perplexity, the game is closer to digital PR and reputation management. These systems lean heavily on third-party mentions, comparison content and community discussion, so getting cited on the sites that these models trust matters more than perfecting your own pages.

Diversifying also protects you against volatility. Similarweb's own tracker, cited by Search Engine Journal, shows how fast rankings can move: writing and content generation sites fell 10% over 12 weeks in one cycle, with several writing tools posting double-digit declines, a reminder that category-level winners and losers can shift quickly even among established players.

Finally, measure across platforms rather than assuming one dataset tells the whole story. Given how much the numbers vary by methodology and time window, it's worth running your own check rather than relying on any single market share report; Sited's free audit at sited.online lets you see how your brand actually appears across ChatGPT, Gemini and other AI systems rather than guessing from aggregate market data.

Frequently asked questions

Does Gemini's growth mean ChatGPT is losing relevance?

No. ChatGPT still holds the largest single share of AI chatbot traffic by most measures, and by standalone app users it still leads with around 900 million weekly active users versus Gemini's 750 million monthly, according to Sitebard. It's losing relative share as the market fragments, not shrinking in absolute terms.

Do I need a different content strategy for Gemini versus ChatGPT?

Broadly yes, because Gemini draws heavily on Google's existing Search index and AI Overviews, so classic SEO fundamentals apply strongly, as Google's own guidance suggests. ChatGPT, Claude and Perplexity rely more on scraped web content, third-party mentions and citations, so digital PR and reputation-building matter more there.

Why is Gemini growing so fast?

Distribution is the main driver. As Techmagnate explains, Gemini is built into Google Search, Android and Workspace, products that billions of people already use, so people encounter it without seeking it out, unlike ChatGPT, which requires a deliberate visit or download.

Should smaller brands worry about optimising for every AI platform?

Not equally. Prioritise based on where your customers actually search. If your audience is consumer-facing and mobile-first, Gemini's reach through Search matters a lot; if your buyers research via long conversational queries or comparison shopping, ChatGPT and Perplexity visibility may matter more.

Is this data likely to keep shifting?

Almost certainly. Market share figures from Similarweb and others, as shown across Search Engine Journal, Sitebard and Stackmatix, have moved by several percentage points within single months this year. Treat any snapshot as a moment in time and recheck your own visibility regularly.