Only 12% of AI Cited URLs Rank in Google’s Top 10 for the Original Prompt

Ahrefs Brand Radar, our data scientist, Xibeijia Guan, searched 15,000 long-tail queries in Google and Bing, then asked those same questions to AI assistants.

Example queries included:

• “How much does it cost to install a security camera?”
• “How to get enough protein when you can’t eat dairy?”
• “What is the cheapest full comprehensive insurance?”
• “¿Cuál es el mejor suplemento para la recuperación muscular?”

Xibeijia then extracted every visible citation returned for each question across both search and AI indices.

In the search dataset, she recorded the ranking positions of the cited URLs—then categorized them based on whether they appeared in the top 10, or top 100 results.

The AI assistants tested include ChatGPT (both in-text citations and bottom-of-response references), Gemini, Copilot, and Perplexity.

According to research carried out by our data scientist, Xibeijia Guan, just 12% of citations in AI assistants also rank in Google’s top 10, on average.

((28.6 + 8 + 6.1 + 8.6 + 8.2) / 5) = 11.9%

80% of those citations don’t rank anywhere in Google for the original query—80% is essentially the average of all the “red” columns in the chart above.

The overlap between AI and search citations is smaller than we anticipated, but we have a couple of theories as to why that might be.

We’ll get into them a little later on.

Perplexity aligns closest to Google

Perplexity is an AI assistant that was literally built to cite—its goal is to support nearly every statement with a source.

Perplexity is the world’s first answer engine. It searches the internet in real time to deliver fast, clear answers to any question—with sources and citations included…Every answer comes with clickable citations, making it easy to verify the information and dig deeper if you want.

Perplexity Team, Oct 2024

ChatGPT and Gemini, on the other hand, don’t always link out.

Their citation process is very much query-dependent, and their internal systems trigger searches based on different criteria.

ChatGPT, for example, seems to use something called the sonic classifier—if the prompt “probability” exceeds a certain threshold (i.e. if the response is less easy to “predict” based on training data), then ChatGPT will perform a web search.

Perplexity consistently favors content that ranks well in Google, with 28.6% of its cited URLs landing in the top 10.

For the other AI assistants, that number hovers around 8%—and more than 80% of their citations come from pages that don’t rank at all for the target query.

Since Perplexity focuses heavily on citations, it seems logical that its results would align closely with Google’s.

But, unlike Gemini and other AI assistants, Perplexity doesn’t draw on Google or Bing’s index. In fact, it has its own search index, based on its crawler: perplexitybot.

AI assistants—even those that draw on Google and Bing—appear to query search indexes in a fundamentally different way. This explains why we’re seeing minimal crossover.