Top 10 Sources LLMs Cite Most in 2026

Last updated: April 2026

A surprising thing happens when you look at the actual data on which domains AI engines cite. No single domain dominates. Evertune’s analysis of 200 million prompts across five months (Evertune) found that even the most-cited domain on any platform rarely exceeds 5 percent of total citations. The combined share of Wikipedia, Reddit, LinkedIn, and YouTube taken together rarely tops 5 percent. The other 95 percent of citations spread across thousands of domains.

That’s a fundamentally different distribution from traditional SEO, where the top 10 results capture roughly two-thirds of clicks. AI search citations are a long tail with a few outliers, not a winner-take-all market.

But the outliers matter. Even at 1-5 percent each, the top-cited domains carry outsized influence on how AI engines describe categories. Knowing which ones rank where, and getting your brand mentioned on those domains, is one of the most direct levers you can pull. This guide ranks the top 10 most-cited sources, drawing on five separate 2025-2026 studies, and explains what each one tells you about your AI visibility strategy.

How we ranked

The rankings below combine four independent data sources: Peec AI’s analysis of 30 million sources (Search Engine Land) across ChatGPT, Google AI Mode, Gemini, Perplexity, and AI Overviews; SEMrush’s analysis of 325,000 unique prompts (ALM Corp); Profound’s analysis of 1.4 million citations across six AI models (ALM Corp); Spotlight’s last-month citation tracking (Spotlight) across six engines; and the SE Ranking analysis of 129,000 unique domains (SE Ranking).

Where the studies disagree, The largest dataset is weighted most heavily, with disagreements noted. The list focuses on share of citations across major AI engines through Q1 2026.

The top 10

1. Reddit

The single most-cited domain across the major AI engines. Peec AI’s 30M-source analysis ranks Reddit #1 across ChatGPT, Google AI Mode, Gemini, Perplexity, and AI Overviews. On Perplexity specifically, Reddit accounts for as many as one in five of all citations (Evertune), the highest concentration of any domain on any platform.

Why it ranks: AI engines treat Reddit threads as authentic, experience-based content with community-validated answers. The signal isn’t link authority, it’s discussion depth. SE Ranking’s 129K-domain study found domains with millions of brand mentions on Reddit averaged 7 ChatGPT citations versus 1.8 for domains with minimal Reddit presence (a 3.9x multiplier).

Strategy: build a real presence in subreddits that map to your category. Answer questions, share specific product experience, contribute frameworks. Promotional posts get filtered out within hours by both moderators and AI ranking signals.

2. LinkedIn

The biggest mover of 2025-2026. Profound’s tracking shows LinkedIn climbed from approximately #11 on ChatGPT in November 2025 to #5 by February 2026, the largest authority shift Profound observed all year (ALM Corp). SEMrush’s 325K-prompt study found LinkedIn cited in 14.3 percent of ChatGPT Search responses, 13.5 percent of Google AI Mode responses, and 5.3 percent of Perplexity responses, behind only Reddit overall.

For professional queries specifically (anything career, B2B, software, or industry related), Profound found LinkedIn is the #1 most-cited domain across all six major AI platforms (ALM Corp).

The split between individual posts and company pages varies by platform: ChatGPT and Google AI Mode pull 59 percent of their LinkedIn citations from individual member content. Perplexity inverts this, pulling 59 percent from Company Pages.

Strategy: have your senior leaders publish substantive thought-leadership posts (not “thought leadership,” actual analysis), and keep your company page active with regular operational content. The dual structure means both efforts compound.

3. YouTube

The strongest single correlation with AI visibility in Ahrefs’ December 2025 75K-brand study (BrandMentions), where YouTube mentions correlated at 0.737 with appearances in ChatGPT, AI Mode, and AI Overviews. AI engines read YouTube transcripts and descriptions, which means a mention in a well-watched video carries the same signal as a mention in a top editorial article.

Spotlight’s last-month data shows YouTube’s citation share is highest on Google AI Mode (1.84 percent of all links) and Perplexity (2.58 percent), reflecting Google’s own preference for its own properties.

Strategy: get your brand mentioned in video reviews, comparisons, and tutorials made by creators in your category. The transcript is what matters; the visual content is incidental for AI extraction. A single 10-minute video that mentions your product can generate citation lift for months.

4. Wikipedia

ChatGPT’s most-cited individual domain. Wikipedia accounts for 7.8 percent of all ChatGPT citations and roughly 22 percent of ChatGPT’s training data (ConvertMate), the highest concentration of any single source. Spotlight’s data confirms Wikipedia at roughly 1.49 percent of all ChatGPT citations in its last-month window.

Strategy: don’t write your own Wikipedia page; that gets reverted by editors who flag conflict of interest. Build the secondary-source coverage (independent press, academic citations, third-party reviews) that makes a notable Wikipedia entry possible over time. If your brand already has an entry, monitor it carefully and ensure factual claims are well-cited and current.

5. Forbes and editorial publications

Forbes ranks in the top five across multiple studies, with editorial publications collectively forming a meaningful citation tier. Spotlight’s data places Forbes alongside Medium and similar publications as Tier-2 most-cited domains on ChatGPT after Reddit and Wikipedia.

The editorial signal works because AI engines treat established publications as confidence-weighted sources. A mention in Forbes carries different signal than a mention in a startup blog, even when the underlying content is similar.

Strategy: prioritize earned editorial mentions over paid placements. AI engines distinguish between sponsored content and editorial mentions through markup and context. Earned mentions work; paid sponsorships often don’t.

6. Review platforms

SE Ranking’s 129K-domain study found domains listed on multiple review platforms (G2, Capterra, Trustpilot, Sitejabber, Yelp) earned 4.6 to 6.3 citations on average versus 1.8 for absent domains. The Peec AI study confirmed that Yelp and G2 specifically appear frequently in recommendation queries across major AI engines.

The mechanism: review platforms function as third-party validation that AI engines treat as authoritative for vendor-comparison and recommendation queries.

Strategy: claim and complete your profile on the major three platforms for your category. Respond to reviews. Encourage satisfied customers to leave structured reviews (star ratings, specific use case mentions, pros/cons format). Generic five-star reviews carry less signal than detailed mid-range reviews.

7. Quora

The 4.1x ChatGPT citation multiplier, the highest of any community platform. SE Ranking’s data: domains with 6.6 million Quora mentions averaged 7 citations versus 1.7 for domains with 33 or fewer mentions. Quora is declining in raw traffic, but its AI citation weight has held up.

Strategy: similar to Reddit, but the platform’s slightly more polished norm means slightly more polished answers work better. Long-form, expert-credentialed answers get cited more than terse community-style replies.

8. NIH and authoritative .gov sources

The SE Ranking study found .gov and .edu domains underperformed commercial domains for general queries (3.2 citations average versus 4.0 for commercial), but they outperform on health, science, finance, and policy queries where authoritative source weighting kicks in. NIH appears in Perplexity’s top five domains specifically.

Strategy: not a deliberate-strategy lever for most brands. But if your category touches healthcare, finance, education, or government, ensure your content cites and links to relevant .gov / .edu sources. Co-citation lifts your own credibility.

9. Medium

A consistent top-10 source on ChatGPT and a Tier-2 citation source elsewhere. Medium’s open publishing platform and aggressive AI training data licensing mean its content reaches AI engines through both retrieval and training pipelines. Medium has lost share to Reddit and LinkedIn in 2025-2026, but remains a viable secondary publication channel.

Strategy: republish or syndicate substantive long-form content on Medium with full author attribution. Don’t post original content there exclusively; it should be a syndication channel, not a primary publishing channel.

10. Substack and newsletters

A rising tier-3 source as AI engines increasingly index newsletter archives. Not yet a top-five source on any platform, but several independent newsletters appear in citation streams for niche B2B queries, particularly in the Profound data.

Strategy: get mentioned in (or write for) the dominant newsletters in your category. The audience is small but the AI citation weight is disproportionately large because newsletters tend to have well-structured archives, expert authors, and authentic editorial framing.

Platform-by-platform patterns

The studies show clear platform-specific differences:

A few takeaways: Reddit is in everyone’s top 5. Google’s AI surfaces favor Google-owned properties (a finding consistent across studies). Perplexity skews toward research-credible sources (NIH, G2 for B2B queries). ChatGPT is the most Wikipedia-heavy.

What this means

The long-tail finding has practical consequences. Trying to rank your own domain higher in AI citations is a slow, structural game (referring domains, brand mentions, content depth). Getting mentioned on the high-citation third-party domains is faster, often with measurable lift in 3-6 weeks.

Three sequenced actions for content teams:

1. Audit which top-10 sources mention your brand today. Run your top 20 category prompts through ChatGPT, Perplexity, and Google AI Mode. Note which competitor names appear and which third-party domains get cited as sources.
2. Pick the two most-cited sources where you’re absent. For most B2B content teams, this will be LinkedIn (if your leaders aren’t publishing there) and one review platform (if your G2/Capterra profiles are empty or thin).
3. Run a 90-day push. Publish weekly LinkedIn content from named senior leaders. Complete your G2 profile, request structured reviews from satisfied customers. Pitch one earned mention per month in a category-relevant editorial publication.

Disclosure: Contently builds Radarly, an AI visibility tracking product that monitors which sources cite your brand across these AI engines.

The teams succeeding at AI visibility are the ones treating it as a third-party-mention problem, not a content production problem. Your own site matters, but it accounts for roughly 25 percent of the citation equation. The other 75 percent lives on the domains in this list.

See where your brand stands

Knowing which sources LLMs cite is half the picture. The other half is knowing whether your brand appears in those citations, in what context, and how that share moves week over week. Contently’s Radarly runs your category prompts across ChatGPT, Perplexity, Gemini, Claude, and Google AI Overviews, then surfaces the source pages each engine pulls from and your share of mentions inside them.

Book a Radarly demo

FAQ

Should I prioritize Reddit or LinkedIn first? Depends on your category. For B2B, professional services, or enterprise software, LinkedIn ranks higher per the SEMrush 325K-prompt study. For consumer brands, lifestyle categories, or any product where authentic experience reviews matter, Reddit ranks higher per Peec AI’s 30M-source data. If you can only run one, look at where your competitors get cited. That’s the tell.

Is paying for a Wikipedia page worth it? No, and it can backfire. Paid Wikipedia editing services almost always produce content that gets reverted within weeks because Wikipedia’s editorial community detects conflict-of-interest contributions reliably. The cleaner path is earning the secondary-source coverage that makes a future organic Wikipedia entry possible. That takes 12-24 months for most brands but produces a stable, hard-to-remove asset.

How often do these rankings change? Faster than you’d expect. The biggest single shift in 2025-2026 was September 2025, when ChatGPT’s citation share for Reddit dropped from roughly 60 percent of prompts to about 10 percent in two weeks, then partially recovered. The platforms tune their citation behavior aggressively, and the rankings cited above will look different by Q4 2026. Audit your AI visibility quarterly, not annually.