Reddit, YouTube, and Wikipedia: Pillars of AI in 2026

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Key Takeaways

1Google's AI Overviews, with 2 billion monthly users, cite YouTube at 20.9%.

2Gemini, used by 750 million people, favors Reddit with 27.5% of citations.

3Microsoft Copilot, integrated into Windows, highlights Amazon and Walmart, with 14.6% and 10.2% of citations, respectively.

💡Why it matters — These platforms significantly influence how AIs generate and present information to users, thereby impacting the visibility of online content.

What websites feed the responses of artificial intelligences in 2026? Ahrefs, with its Brand Radar tool, analyzes the most cited domains each month by five AI engines: Google AI Overviews, Gemini, Microsoft Copilot, Grok, and Perplexity. This study is based on American queries and stops as of June 1, 2026. One observation stands out: despite specific preferences for each AI, Reddit, YouTube, and Wikipedia almost systematically appear.

Google AI Overviews: YouTube and Reddit Lead the Way

Google's AI Overviews, which top search results, reach over two billion monthly users. According to Ahrefs, YouTube is the most cited source with 20.9% of citations, followed by Reddit at 19.6% and Facebook at 11.6%. Google itself ranks fourth with a share of 6%, marking significant growth. Instagram, Wikipedia, Amazon, Quora, TikTok, and Walmart complete the top 10, illustrating a diversity of sources ranging from social networks to e-commerce platforms.

youtube.com (20.9%)
reddit.com (19.6%)
facebook.com (11.6%)
google.com (6.0%)
instagram.com (5.2%)
en.wikipedia.org (4.8%)
amazon.com (4.0%)
quora.com (4.0%)
tiktok.com (3.6%)
walmart.com (0.9%)

Gemini: Reddit Captures More Than a Quarter of Citations

Integrated into search, Android, Chrome, and Workspace, Gemini claims over 750 million monthly active users. According to Sundar Pichai, Reddit dominates with 27.5% of citations, more than double that of YouTube (13.7%) and Wikipedia (12.7%). The rest of the ranking, significantly behind, includes various media and retail sites such as Forbes, Walmart, eBay, Edmunds, KBB, Car and Driver, and Business Insider. These figures show a marked preference for user-generated content platforms and online encyclopedias.

reddit.com (27.5%)
youtube.com (13.7%)
en.wikipedia.org (12.7%)
forbes.com (2.9%)
walmart.com (2.8%)
ebay.com (1.9%)
edmunds.com (1.7%)
kbb.com (1.7%)
caranddriver.com (1.6%)
businessinsider.com (1.4%)

Microsoft Copilot: Amazon and Walmart Take the Lead

Distributed across Windows, Edge, Bing, and Microsoft 365, Copilot claims over 100 million monthly active users and around 800 million people interacting with its AI features. Its source profile is significantly more commercial: Amazon (14.6%) and Walmart (10.2%) dominate, ahead of Wikipedia (9.6%). This commercial orientation is reinforced by the integration of shopping and payment into Copilot conversations. Reddit, YouTube, Target, EngineerFix, Etsy, Forbes, and BestBuy also appear in the rankings, highlighting the importance of e-commerce platforms and news sites.

amazon.com (14.6%)
walmart.com (10.2%)
en.wikipedia.org (9.6%)
reddit.com (4.9%)
youtube.com (3.5%)
target.com (3.3%)
engineerfix.com (3.0%)
etsy.com (2.8%)
forbes.com (2.8%)
bestbuy.com (2.2%)

Grok: Social Networks Enter the Top 5

Grok, the xAI assistant integrated into X, draws heavily from social networks. According to SpaceX, 117 million people use its features each month. Reddit (16.3%) narrowly leads YouTube (15.1%) and Facebook (13.9%), while Instagram, Quora, and TikTok round out the top spots. Six of the ten most cited sources are community or social platforms, reflecting the importance of social interactions and user-generated content in the responses provided by Grok.

reddit.com (16.3%)
youtube.com (15.1%)
facebook.com (13.9%)
instagram.com (5.9%)
quora.com (5.5%)
amazon.com (5.0%)
tiktok.com (4.8%)
en.wikipedia.org (3.4%)
ebay.com (1.5%)
walmart.com (1.5%)

Perplexity: YouTube Accounts for Nearly a Third of Sources

Perplexity, designed to display its sources, shows the highest concentration of any of the platforms and claims tens of millions of active users. YouTube alone captures 32.4% of citations, ahead of Reddit (16.6%) and Wikipedia (8.2%). Following are several marketplaces like Alibaba and Etsy, indicating a strong product focus in purchase-related queries. Target, LinkedIn, Edmunds, and Walmart also rank among the most cited sources, illustrating the diversity of information available on Perplexity.

youtube.com (32.4%)
reddit.com (16.6%)
en.wikipedia.org (8.2%)
alibaba.com (5.1%)
oreateai.com (2.9%)
etsy.com (1.8%)
target.com (1.6%)
linkedin.com (1.4%)
edmunds.com (1.3%)
walmart.com (1.3%)

Reddit, YouTube, and Wikipedia: Safe Havens for AIs

Beyond the specifics of each engine, three domains appear in all rankings: Reddit, YouTube, and Wikipedia. Community content, video, and the collaborative encyclopedia form the common foundation upon which AIs rely to formulate their responses. For SEO professionals, these platforms are becoming significant visibility levers, on par with positions in traditional search results.