As of mid-2026, YouTube is the single most-cited domain in Google AI Overviews, at about 20.9% mention share, narrowly ahead of Reddit. The top of the list is dominated by video, community, and social platforms, not brand-owned sites. This is a dated, fully-attributed reference to which domains Google's AI Overviews pull from most, why you'll see two different numbers quoted for YouTube, and what the pattern means for your own site.
Last reviewed: 19 July 2026. The share table below is from Ahrefs' Brand Radar, tracking every domain AI Overviews cited across more than 3 million US queries (published 1 June 2026). The out-of-top-100 and all-citation figures are from a separate Ahrefs analysis of 863,000 keyword SERPs and 4 million AI Overview URLs (data as of 2 March 2026). Both are single-vendor (Ahrefs), specific to Google's AI Overviews rather than every AI engine, and directional.
Which domains does Google AI Overviews cite most?
Here is Ahrefs' ranked list of the top-cited domains in Google AI Overviews, by mention share, which Ahrefs defines as a domain's citations as a percentage of the summed citations of the top sources:
| Rank | Domain | Mention share | Type |
|---|---|---|---|
| 1 | youtube.com | ~20.9% | Video |
| 2 | reddit.com | ~19.6% | Community |
| 3 | facebook.com | ~11.6% | Social |
| 4 | google.com | ~6.0% | Search / owned |
| 5 | instagram.com | ~5.2% | Social |
| 6 | en.wikipedia.org | ~4.8% | Reference |
| 7 | amazon.com | ~4.0% | Commerce |
| 8 | quora.com | ~4.0% | Community |
| 9 | tiktok.com | ~3.6% | Video |
| 10 | walmart.com | ~0.9% | Commerce |
Source: Ahrefs Brand Radar, published 1 June 2026 (3M+ US queries). The one-line read: AI Overviews cite video, community, and social platforms far more than any brand's own site. Ahrefs counted 1,545,623 distinct YouTube pages cited, which is what pushes it to the top.
Wait, is YouTube really cited more than Reddit?
Inside Google AI Overviews, yes, but the two are close enough to call co-leaders. YouTube's ~20.9% mention share edges Reddit's ~19.6%. The scope matters, though. Our reconciliation of the citation-concentration studies notes Reddit is the more commonly reported #1 source across engines such as ChatGPT and Perplexity. There's no contradiction: this page is about Google AI Overviews specifically, where video leads, while Reddit's crown is an across-engine, community-heavy result. "Most-cited" always needs an engine and a denominator attached.
That denominator point also explains a number mismatch you'll come across. You'll see YouTube quoted at both ~20.9% and ~5.6%, and both are correct:
| What's being measured | YouTube figure | Source (date) |
|---|---|---|
| Mention share among the top cited sources | ~20.9% | Ahrefs Brand Radar (Jun 2026) |
| Share of all AI Overview citation URLs | ~5.6% | Ahrefs, 863K SERPs (Mar 2026) |
| Share of citations that ranked outside Google's top 100 | ~18.2% | Ahrefs, 863K SERPs (Mar 2026) |
The ~20.9% is a share of the top sources' citations; the ~5.6% is a share of every citation across the whole dataset. Different denominators, same underlying reality: YouTube is the most-cited single domain either way. Read the pattern, not the point estimate.
Why does Google AI Overviews lean on YouTube and social so heavily?
Three durable reasons, not a quirk of one month:
- Google owns YouTube. Google can index and understand YouTube's multimodal content, transcripts included, more readily than the open web, and it has an obvious incentive to surface its own video property in answers.
- Community content carries first-hand experience. Reddit, Quora, and forums hold the lived, specific answers Google's quality guidance keeps asking for, which is why they sit alongside video at the top.
- AI Overviews citation is decoupling from classic rank. Ahrefs found only about 38% of AI Overview citations now come from pages ranking in Google's top 10, down from about 76% a year earlier, and roughly 18.2% of the citations that ranked outside the top 100 were YouTube URLs. We unpack that rank-decoupling in does ranking on Google get you cited by AI. A page no longer has to rank to be cited, which opens the door to video and community sources.
In Google AI Overviews, the most-cited domain isn't a publisher or a brand. It's YouTube, narrowly ahead of Reddit. Video and community are where AI answers are sourced, and a classic top-10 ranking is no longer the price of admission.
What does this pattern mean for your own domain?
That your homepage is unlikely to be the thing AI Overviews cites, and that's the point. Even the largest commercial domains sit low on the list (Amazon ~4.0%, Walmart ~0.9%), so the leverage is in earning presence on the platforms AI Overviews already trusts, then backing it with entity strength:
- Publish extractable video. Because YouTube is the #1 cited domain and Google owns it, well-structured video is a high-leverage, low-crowd surface. The method is in how to earn AI Overview citations from YouTube video, and the concept is video AEO.
- Take community seriously. Reddit and Quora carry real citation weight; see how to use Reddit for AI search visibility.
- Build entity strength that travels. A separate Ahrefs study of 75,000 brands (released May 2026) reported YouTube mentions correlated with AI brand visibility more strongly than any other metric, while link volume and page count correlated only weakly. Consistent, corroborated presence is the durable lever: entity strength for AI search.
- Measure where you're actually cited. Which domains an engine cites in aggregate is context; whether your brand shows up, on each engine, over time, is the signal. That's how to measure AI visibility.
The domain leaderboard tells you where AI Overviews look for answers. What decides your visibility is whether your content, on the surfaces those engines trust, actually gets named and cited, measured on your own footprint and across engines over time. That is exactly what Buffy Intel is built to track.