Semrush Study Reveals Why Most Brands Are Invisible to AI

Semrush has published its expanded 2026 AI Visibility Index, analysing 126 million US AI search prompts across ChatGPT, Gemini, Google AI Mode and Google AI Overviews. The headline finding is that visibility is now highly concentrated in a handful of categories, with only 36 brands appearing in the top 100 on every platform every month, and that being mentioned by an AI system is not the same as being cited as its source. For most businesses, this confirms that AI search visibility needs active management, not an assumption that good old SEO will carry over automatically.

What changed?

Semrush launched the original AI Visibility Index in September 2025 with a sample of 2,500 prompts. The new 2026 edition is a different order of magnitude entirely.

The expanded study analysed 126 million US AI search prompts from January through April 2026, making it one of the largest datasets yet assembled on how brands are mentioned, cited and represented inside AI-powered discovery tools. That scale matters because it moves the conversation from anecdote to pattern: this is close to a census of how real people ask AI systems about brands, not a handful of test prompts.

The report arrives at a moment when, as HubSpot notes, ChatGPT now processes over 2.5 billion prompts per day, and industry analysts expect AI-driven search traffic to overtake traditional search by 2028.

What does the data actually show?

The most striking finding is how unevenly visibility is spread across industries. Semrush found that in News and Media, the three most visible brands accounted for 82.9% of total category visibility, while in Consumer Electronics the top three represented 76.9%. By contrast, visibility was far more distributed in Finance, where the top three brands accounted for 41.4%, and Industrial, where they represented 42.2%.

That gap matters for strategy. Semrush's own analysis suggests these less concentrated categories may offer greater opportunities for brands to gain visibility over time, because the field hasn't already been locked up by three dominant names.

Consistency across platforms is rare. Only 36 global brands maintained top-100 visibility across all four platforms during every month of the study, a group Semrush calls the "Universal 36", including YouTube, Google, Reddit, Amazon, Facebook, Apple, Walmart, Disney and Nintendo. Everyone else appears inconsistently: strong on one platform in one month, absent the next.

The platforms themselves behave very differently when it comes to sourcing their answers. Semrush found that ChatGPT cites an average of 15 sources per response and frequently relies on community and reference platforms such as Reddit and Wikipedia, while Gemini cites an average of just 3 sources per response, drawing on a smaller pool that includes Wikipedia, Reddit and YouTube. A brand optimised for one platform's citation habits could easily be invisible on another.

Perhaps the most important nuance for marketers is the distinction between being talked about and being credited. Semrush is explicit that brand mentions and citations measure different forms of visibility, and being mentioned in an AI-generated answer does not necessarily mean a brand's own website is cited as the supporting source. An AI system can describe your product accurately while sending all the credibility, and the click, to a third-party review site or forum thread instead of you.

Why does this matter for your business?

This is no longer a niche concern for SEO specialists. As Pew Research data highlighted by HubSpot shows, Google's AI Overviews already appeared in 18% of US searches, and that share is climbing. If your brand isn't part of the source mix behind those answers, you are effectively absent from a growing share of the discovery journey, even if your traditional rankings look healthy.

The concentration data is both a warning and an opportunity depending on your sector. If you sell consumer electronics or operate in news and media, Semrush's findings suggest the top three brands already dominate AI answers in your category, which makes displacement hard but not impossible. If you're in finance or industrial sectors, the more distributed picture means there's genuine room to build visibility before a small group of incumbents locks it down.

The mentions-versus-citations gap is arguably the most actionable insight here. A brand can be name-checked constantly by AI tools while getting none of the traffic, trust transfer or link equity that comes from being the cited source. As Andrew Warden, Vice President of Marketing at Adobe and former CMO of Semrush, put it in Semrush's announcement, the foundations of SEO remain critically important for creating trust signals, but visibility now depends on how consistently a brand reinforces its narrative across every digital channel, not just its own website.

What should you do now?

Start by finding out where you currently stand. Before you can fix a visibility gap, you need to know whether AI systems mention you at all, and separately, whether they cite you as the source when they do. This is exactly the kind of check-up Sited's free audit at sited.online is built for, giving you a quick read on how your brand currently shows up across AI answer engines.

Once you know your baseline, treat each platform separately rather than assuming one strategy fits all. Given that ChatGPT draws on roughly 15 sources per answer including community platforms, while Gemini draws on around 3, a presence on Reddit and Wikipedia may do more for ChatGPT visibility than a polished product page ever will, while Gemini visibility depends on a narrower, more concentrated set of trusted sources.

Prioritise being cited, not just mentioned. That means making sure your own pages contain the specific facts, figures and direct answers that AI systems can lift and attribute, rather than generic marketing copy that gets paraphrased and credited to someone else.

Finally, revisit your category's concentration level. If you're in a fragmented category like finance or industrial, act now while the field is still open. If you're in a concentrated category like consumer electronics or media, focus on niche queries and specific use cases where the dominant three brands are less likely to be the default answer.

Frequently asked questions

What is the Semrush 2026 AI Visibility Index?

It's a flagship study from Semrush that analysed 126 million US AI search prompts from January to April 2026 across ChatGPT, Gemini, Google AI Mode and Google AI Overviews, expanding on an original 2,500-prompt study launched in September 2025.

What is the "Universal 36"?

It's Semrush's name for the group of 36 global brands that maintained top-100 visibility across all four AI platforms studied, every month, including names like YouTube, Google, Amazon and Apple. Almost every other brand's visibility fluctuates month to month and platform to platform.

Is being mentioned by ChatGPT or Gemini the same as being cited?

No. Semrush's data shows brand mentions and citations measure different forms of visibility, and an AI-generated answer can mention a brand without citing that brand's own website as the source. You want both, but citation is what typically drives referral traffic and trust.

Which industries have the most room to gain AI visibility right now?

According to Semrush, Finance and Industrial are the least concentrated categories, with the top three brands accounting for only 41.4% and 42.2% of visibility respectively, compared with over 80% in News and Media. That makes them more accessible for brands trying to build AI visibility from scratch.

Why does Gemini cite fewer sources than ChatGPT?

Semrush's study found that Gemini cites an average of just 3 sources per response compared with ChatGPT's average of 15, suggesting it draws on a smaller, more curated pool. The exact reasons aren't disclosed by Google, but it means brands need a more concentrated, high-authority footprint to be picked up there.