The 10 Most Mentioned Domains for ChatGPT, Perplexity, and AI Overviews Across 78.6M Searches

Curious about which websites AI assistants reference the most? I set out to find the most frequently cited sources across major AI systems, offering insight into which sites are being prioritized and trusted by each platform.

To do this, I analyzed the top 10 websites cited in Google’s AI Overviews, ChatGPT, and Perplexity, using data from Ahrefs Brand Radar. This includes insights from:

• ~76.7 million Google AI Overviews
• 957,000 ChatGPT prompts
• 953,500 Perplexity prompts
• All tracked in June 2025

Side note: Brand Radar isn’t your typical LLM visibility tool. Unlike basic rank trackers, it monitors a vast volume of queries across various AI systems. Think of it more like a Site Explorer for AI-driven search, letting you analyze product, service, or brand visibility and benchmark against competitors.

Mention share for top domains across AI assistants

Mention Share measures how often the model chooses a domain. Here’s a comparison across AI assistants:

While Wikipedia leads across the board, its prominence varies:

• ChatGPT references Wikipedia the most (16.3%)
• Followed by Perplexity (12.5%)
• Then Google AI Overviews (8.4%)

Interestingly, YouTube ranks highest in Perplexity (16.1%) and AI Overviews (9.5%), but doesn’t even make the top 10 in ChatGPT, highlighting a difference in content type preference—Perplexity and Google lean toward multimedia sources, while ChatGPT tends to favor text-based information.

Platforms like Reddit and Quora appear almost exclusively in AI Overviews (7.4% and 3.6% respectively), suggesting that Google is more inclined to elevate user-generated content, unlike ChatGPT and Perplexity.

On the flip side, ChatGPT heavily cites news outlets like Reuters, Apple News (AP), and AS.com, with visibility ranging from 4% to 2.6%. These sources don’t feature as prominently in Google or Perplexity, reinforcing ChatGPT’s bias toward authoritative news media.

In the health and medical space, Mayo Clinic and the Cleveland Clinic appear in AI Overviews, while ChatGPT and Perplexity omit them from their top 10. However, Perplexity surfaces more niche health sites like Tua Saúde and Alodokter, indicating a broader, possibly localized, scope of sources.

Impression share / potential reach for top domains across AI assistants

It’s important to note: not all citations are equal. Some topics and sources are referenced in high-volume searches, while others appear in niche or less-searched queries.

To better understand the visibility and impact of these citations, we looked beyond raw mention counts. Since there’s no standard “search volume” for AI assistant prompts, we used Google search volume as a proxy to estimate how prominent or visible these citations might be.

We applied two key metrics:

• Impression Share – The number of times a site is cited, weighted by the Google search volume of those keywords, to reflect how visible the source is in popular queries.
• Potential Reach – Similar to impression share, but focused on estimating the overall exposure a site could get, based on how often it’s cited in high-traffic searches.

This approach offers a more realistic view of which sites aren’t just cited frequently, but are visible in high-impact, high-interest AI responses.

Impression share / potential reach by AI assistant

Here are the top 10 websites by Impression Share / Potential Reach for each AI assistant:

How Engage Coders Can Help

At Engage Coders, we specialize in AI-powered content marketing and SEO analytics. From analyzing AI visibility metrics to building strategies that increase your brand’s presence across AI assistants, we help businesses stay competitive in the evolving search landscape.

Looking to boost your AI visibility? Let’s connect and build a smarter strategy for your brand.