Data & Studies

Google Seems More Biased Towards Big Brands Than ChatGPT and Perplexity

Patrick Stox
Patrick Stox is a Product Advisor, Technical SEO, & Brand Ambassador at Ahrefs. He was the lead author for the SEO chapter of the 2021 Web Almanac and a reviewer for the 2022 SEO chapter. He also co-wrote the SEO Book For Beginners by Ahrefs and was the Technical Review Editor for The Art of SEO 4th Edition. He’s an organizer for several groups including the Raleigh SEO Meetup (the most successful SEO Meetup in the US), the Beer and SEO Meetup, the Raleigh SEO Conference, Tech SEO Connect, runs a Technical SEO Slack group, and is a moderator for /r/TechSEO on Reddit.
Does being mentioned more on the web lead to more mentions in AI assistants? I’m defining mentions as the number of web pages that mention an entity at least once.

I looked at the top 50 websites mentioned in Ahrefs Brand Radar for Google AI Overviews, ChatGPT, and Perplexity.

This is across ~76.7M AI Overviews, 957k ChatGPT prompts, and 953.5k Perplexity prompts for the month of June 2025.

Let’s dig in.

I’ll give the usual correlation does not equal causation disclaimer.

Google has a strong correlation, where it seems like branded web mentions lead to more visibility. The others did not correlate as well.

branded web mentions vs AI visibility correlations

We saw nearly the same correlation for AI Overviews across 75,000 websites. In fact, Branded web mentions were the highest correlating factor. Here’s the data from that study.

Factors that correlate with brand appearance in AI Overviews across 75k brands

However, Perplexity and ChatGPT did not correlate nearly as much. Perplexity had a weak correlation and ChatGPT a very weak correlation.

Google has favored brands for a long time, and the other AI assistants may not have the same built-in systems for it that Google does. Google favors brands to fight false information, to lean into trusted content. Google’s former CEO Eric Schmidt was once asked about the internet becoming a cesspool where false information thrives. He said:

Brands are the solution, not the problem.
Eric Schmidt, Former Google CEO

Here are the Spearman rank correlations for branded web mentions vs. AI visibility across the top 50 domains in each system:

AI Assistantρ (Mentions vs Visibility)Correlation
Google AI Overviews0.65Strong
ChatGPT0.15Very Weak
Perplexity0.30Weak

Final thoughts

We’ll run this on a larger sample of sites and see if anything changes, but considering how well the results for Google AI Overviews lined up with the larger study, I’m not sure they will change much.

In the meantime, check out Brand Radar. Brand Radar isn’t just another LLM visibility monitor, we track a large amount of queries across all of these systems and you can query for any product, service, or brand and compare vs competitors. It’s more like Site Explorer than it is Rank Tracker. Plus we have the web visibility index so that you can see how you’re talked about online and the search demand index to see how popular you are in searches.