AI visibility is a measure of how often a brand appears in the answers given by AI assistants (ChatGPT, Gemini, Perplexity, Claude, Copilot) and in Google's AI features, such as AI Overviews and AI Mode. You measure it differently from SEO, because there's no fixed position: the answers change every time someone asks.
A January 2026 study by SparkToro and Gumshoe showed this clearly. Across 2,961 answers to 12 questions, the chance that two answers contained the same list of brands was less than one in a hundred. The chance of the same list in the same order was roughly one in a thousand. Rand Fishkin drew the right conclusion: measure the percentage of answers you appear in, not your "position".
What to measure
Five metrics, from the simplest to the most expensive to collect.
| Metric | What it tells you | Where to get it |
|---|---|---|
| Traffic from AI assistants | How many people reach your site from the answers | GA4, AI Assistant channel or regex |
| Impressions in AI Overviews and AI Mode | How often your pages are shown in Google's answers | Search Console, AI report |
| Mention rate | The percentage of answers that name the brand | A sample of repeated questions, by hand or with a tool |
| Citation rate | The percentage of answers that cite your site as a source, with a link | Same sample |
| Share of voice | How often you appear compared with competitors | Same sample, including competitors |
A citation and a mention are not the same thing. A citation is a link to one of your pages, used as a source. A mention is the brand name in the text. AirOps found that brands that are both cited and mentioned are 40% more likely to turn up again in the next answer. There's more on this in our article on AI citations and mentions.
AI traffic in GA4
Since May 2026 GA4 has had a default channel called AI Assistant, with the medium ai-assistant. Google gives ChatGPT, Gemini and Claude as examples, but doesn't publish the full list of sources it includes.
Two limits worth knowing:
- traffic that arrives without a referrer (from the ChatGPT app, from copied links, from in-app browsers) ends up in Direct;
- OpenAI adds
utm_source=chatgpt.comto the links in its answers (source), so some of it can be recovered from the parameters.
If you want a check of your own, create a custom channel group with a regex on the source. This is a short version of the one published by Analytics Mania, whose full version covers more than 100 domains:
chatgpt\.com|chat\.openai\.com|gemini\.google\.com|perplexity(?:\.ai)?|claude\.ai|copilot\.microsoft\.com|deepseek\.com|(?:\w+\.)?meta\.ai|grok\.com|(?:\w+\.)?mistral\.ai|you\.com|phind\.comHow big is this traffic? Small, for now. Conductor's benchmark of 13,770 domains and 3.3 billion sessions put it at 1.08% of visits, 87.4% of them from ChatGPT. On our own site, whose audience is mostly Italian, the logs from 31 August to 27 September 2026 show 18 human visits with a chatgpt.com referrer against 175 from google.com. Perplexity, Gemini and Copilot sent none.
What makes up for the low volume is quality. Ahrefs measured on its own site that AI traffic is 0.5% of the total but brings in 12.1% of sign-ups. That's one site and it shouldn't be generalised, but it points the same way as what we see with B2B clients: fewer leads, further along in their decision.
Search Console: the AI report
Since 31 August 2026 Search Console has shown impressions for pages that appear in AI Overviews and AI Mode, broken down by page, country, device and date. It doesn't show clicks, CTR or queries. In the UK both features are live: AI Mode started rolling out on 28 July 2025. We've covered the report in detail in how AI Overviews affect SEO.
It's useful for seeing which pages Google uses in its answers. It doesn't tell you whether they did any good.
The question sample
For mentions, citations and share of voice you need a fixed sample of questions, repeated over time on the same engines. Every tool works this way, and you can do it by hand too.
- Write 30-50 questions your customers actually ask: "which X supplier for Y", "how much does Z cost", "difference between A and B". Leave the brand name out of half of them.
- Pick the engines that matter to your audience. In the UK ChatGPT accounts for 80% of referral traffic from chatbots and Gemini for 10%, according to StatCounter for September 2026. Copilot is third, at 5.6%.
- Repeat each question at least 3 times per engine, because the answers vary.
- Record whether the brand is named, whether the site is cited, which competitors appear and which sources are used.
- Run the whole thing again every month, with the same questions.
Here's an example from our own test on 27 September 2026, run in Italian for the Italian market. Asked "which SEO agency should a manufacturing company in Lombardy choose?", ChatGPT named Visilay and cited our article on SEO for manufacturing. Perplexity, Gemini and Claude didn't. Had we measured ChatGPT alone, we'd have come away with a picture that was far too rosy. The full test is written up in our article on AI search engines.
The tools
Running the sample by hand is fine to start with. Beyond 50 questions you need a tool. Entry prices as checked on the official pages on 27 September 2026, in US dollars because that's how the vendors list them (none of the four publishes a sterling price):
| Tool | From | What's included |
|---|---|---|
| Otterly | $29/month | 15 prompts |
| Semrush AI Visibility Toolkit | $99/month | 25 tracked prompts |
| Ahrefs Brand Radar | $50/month per platform | Custom prompts, $699 for all models |
| Profound | Free trial | Enterprise plans quoted on request |
A wider comparison, with pros and cons, is in our guide to the best AI visibility tools. For AI Overviews specifically, see the one on AI Overview tools.
For clients we use a dashboard built on the DataForSEO APIs, which queries ChatGPT, Claude, Gemini, Perplexity and Google's AI Overviews on hundreds of questions per project. The advantage over an off-the-shelf tool is that the questions and competitors fit the sector, even with thousands of prompts.
A sample dashboard
There are five views you actually need:
- overview: mention rate for the brand and its competitors, month on month;
- by engine: the same metric split across ChatGPT, Gemini, Perplexity, Claude and AI Overviews;
- by topic: questions grouped by subject, to see where the brand is strong and where it's missing;
- sources: the domains cited most often in answers about your sector, in other words the sites where it pays to get mentioned;
- traffic: visits from the AI Assistant channel, and conversions.
The sources view is the one that tells you what to do. If the most-cited sources in your sector's answers are three trade portals and a magazine, that's where your digital PR work starts.
How often to measure
Once a month for the question sample, because the answers shift all the time and measuring more often mostly records noise. Once a week for GA4 traffic, alongside your other channels.
If you'd like a snapshot of where you stand today, it's the first thing we do in our GEO service: a sample of questions from your sector, the competitors that show up and the sources that matter.
FAQs
It's a measure of how often a brand appears in the answers of AI assistants such as ChatGPT, Gemini and Perplexity, and in Google's AI features. It's expressed as the percentage of answers that name or cite the brand, across a fixed sample of questions.
Through the default AI Assistant channel, introduced in May 2026, or with a custom channel group that uses a regex on the source covering domains such as chatgpt.com, perplexity.ai, gemini.google.com and claude.ai. Some traffic without a referrer will still land in Direct.
No. The answers change every time: a 2026 SparkToro study found less than a one-in-a-hundred chance that two answers contain the same list of brands. It makes more sense to measure the percentage of answers you appear in.
As of September 2026, prices start at $29 a month for 15 prompts with Otterly, $99 for 25 prompts with the Semrush AI Visibility Toolkit and $50 per platform with Ahrefs Brand Radar. None of them lists a sterling price. Enterprise plans are quoted on request.
