ObsurfableA month is a long time in AI citation. Rankings that look stable at the top still reshuffle underneath — dictionaries climb into ChatGPT's top 10, YouTube collapses on one engine and dominates another, and Google's own properties keep rising on Google AI surfaces.
This August 2026 report updates our July 2026 leaderboard with the latest public Brand Radar monthly snapshots from Ahrefs — plus corroborating mid-2026 studies from SurfacedBy, CiteMetrix, Everything-PR, and others. The headline domains have not changed. The platform-level story has gotten sharper.
Consensus leaderboard: still Reddit, YouTube, Wikipedia
Across engines, the same three platforms keep the top slots. Exact mention share depends on the engine and methodology, but the ordering at the very top barely moves:
| Rank | Domain | Role in AI answers |
|---|---|---|
| 1 | First-hand discussion for evaluation and "which is best" queries | |
| 2 | YouTube | How-to, review, and demo evidence — especially Google AI Overviews and Perplexity |
| 3 | Wikipedia | Entity and definitional trust anchor — especially ChatGPT |
| 4 | Facebook / Instagram / Quora | Social and Q&A layers that matter far more on Google surfaces than on ChatGPT |
| 5 | google.com | Self-citation via Business Profiles and knowledge panels in AI Mode / AI Overviews |
| 6 | Forbes / Healthline / Consumer Reports | Editorial and review authority for commercial and consumer queries |
| 7 | Amazon / Walmart / Target | Commerce and product evidence |
| 8 | NIH / PubMed / dictionaries | Primary research and reference — rising hard on ChatGPT |
Everything-PR's synthesis of 680M+ citations still puts Reddit near ~40% multi-engine aggregate frequency in some methodologies, with the top 15 domains capturing roughly 68% of consolidated citation share. SurfacedBy's controlled sample of 127,198 citations across five engines found only 2.7% of domains cited by all five — and 69.6% cited by exactly one. Concentration at the top and fragmentation underneath remain the defining structure.
Hard numbers by platform (Ahrefs Brand Radar)
Ahrefs publishes monthly "50 most-cited" tables by assistant, scored by mention share — each domain's citations as a percentage of the summed citations of the top sources. Latest public snapshots (US, all topics):
ChatGPT
| Rank | Domain | Mention share | MoM signal |
|---|---|---|---|
| 1 | reddit.com | 16.7% | Stable |
| 2 | en.wikipedia.org | 8.9% | Stable |
| 3 | forbes.com | 3.3% | ▲ 1 |
| 4 | merriam-webster.com | 3.1% | ▲ 13 |
| 5 | engineerfix.com | 3.0% | ▲ 4 |
| 6 | legalclarity.org | 2.9% | ▲ 13 |
| 7 | consumerreports.org | 2.8% | ▲ 6 |
| 8 | healthline.com | 2.7% | ▼ 1 |
| 9 | walmart.com | 2.6% | ▼ 3 |
| 10 | dictionary.cambridge.org | 2.5% | ▲ 21 |
What changed: Reference and dictionary sites are the month's climbers — Cambridge Dictionary jumped 21 places, Dictionary.com 24, Merriam-Webster 13. YouTube sits at only 1.8% (▼ 11) — a reminder that video dominance is not universal. LinkedIn entered the top 50 as NEW. ChatGPT remains the most encyclopedia- and editorial-heavy major assistant.
Perplexity
| Rank | Domain | Mention share | MoM signal |
|---|---|---|---|
| 1 | youtube.com | 31.2% | Stable (most concentrated #1 of any assistant) |
| 2 | reddit.com | 13.9% | Stable |
| 3 | en.wikipedia.org | 7.2% | Stable |
| 4 | alibaba.com | 3.3% | Stable |
| 5 | facebook.com | 2.7% | ▲ 7 |
| 6 | edmunds.com | 2.0% | ▲ 3 |
| 7 | shop.tiktok.com | 1.9% | NEW |
| 8 | target.com | 1.9% | ▼ 1 |
| 9 | oreateai.com | 1.8% | ▼ 4 |
| 10 | kbb.com | 1.7% | ▲ 3 |
What changed: YouTube's 31.2% share is still the most extreme single-domain concentration Ahrefs reports on any assistant. Commerce and vertical review sites (Alibaba, Edmunds, KBB, Target, Amazon NEW) fill the next tier. TikTok Shop appearing as NEW signals social-commerce retrieval, not just organic video.
Google AI Overviews
| Rank | Domain | Mention share | MoM signal |
|---|---|---|---|
| 1 | youtube.com | 21.1% | Stable |
| 2 | reddit.com | 18.5% | Stable |
| 3 | facebook.com | 10.7% | Stable |
| 4 | google.com | 7.1% | Stable |
| 5 | instagram.com | 5.8% | Stable |
| 6 | quora.com | 5.0% | ▲ 2 |
| 7 | en.wikipedia.org | 4.8% | ▼ 1 |
| 8 | amazon.com | 3.5% | ▼ 1 |
| 9 | tiktok.com | 3.2% | Stable |
What changed: Google's SERP-integrated AI surface remains a UGC + Google ecosystem game. YouTube + Reddit alone exceed 39% combined mention share among top sources. Facebook, Instagram, Quora, and google.com deepen the social/self-citation layer that barely appears in ChatGPT's top 10.
Google AI Mode
| Rank | Domain | Mention share | MoM signal |
|---|---|---|---|
| 1 | reddit.com | 19.9% | Stable |
| 2 | youtube.com | 17.0% | Stable |
| 3 | google.com | 11.5% | ▲ 1 |
| 4 | facebook.com | 9.3% | ▼ 1 |
| 5 | instagram.com | 5.3% | Stable |
| 6 | en.wikipedia.org | 4.9% | Stable |
| 7 | quora.com | 2.6% | ▲ 1 |
| 8 | amazon.com | 2.4% | ▼ 1 |
| 9 | tiktok.com | 2.1% | Stable |
| 10 | walmart.com | 1.8% | Stable |
What changed: AI Mode flips AIO's #1/#2 — Reddit leads, YouTube is close second. google.com at 11.5% (▲ 1) continues the self-citation shift toward Business Profiles and product panels. AI Mode and AI Overviews still share only ~11–14% of cited URLs on matched prompts (Ahrefs / MaxAEO panels) — treat them as separate scoreboards.
Side-by-side: same domain, different engines
| Domain | ChatGPT | AI Mode | AI Overviews | Perplexity |
|---|---|---|---|---|
| 16.7% | 19.9% | 18.5% | 13.9% | |
| YouTube | 1.8% | 17.0% | 21.1% | 31.2% |
| Wikipedia | 8.9% | 4.9% | 4.8% | 7.2% |
| — | 9.3% | 10.7% | 2.7% | |
| google.com | — | 11.5% | 7.1% | — |
| Forbes | 3.3% | 0.9% | 0.8% | 0.7% |
YouTube is nearly 17× more important on Perplexity than on ChatGPT by mention share. Forbes is roughly 4× more important on ChatGPT than on Google AI Overviews. A single "get cited by AI" playbook cannot cover these gaps.
CiteMetrix's broader finding still holds: only about 11% of cited domains overlap between ChatGPT and Perplexity. SurfacedBy put all-five-engine domain overlap at 2.7%. See Why Each AI Engine Reads a Different Search Index.
Claude: the outlier that barely cites Reddit or YouTube
Claude still does not look like the other assistants. SurfacedBy's five-engine sample found Claude sent 0.02% of citations to YouTube and 0.01% to Reddit — while listing 6.8 sources per answer on average. It pulls from documentation, vendor pages, and prestige editorial instead.
Independent 2026 Claude analyses consistently place Wikipedia, The New York Times, The Atlantic, The Economist, FT, Reuters, NIH/PubMed, and academic domains at the top of its preference set. Social citation rates sit near floor levels. If your buyers use Claude, a YouTube-and-Reddit strategy is the wrong primary bet — earned coverage in high-trust editorial and institutional sources is the path.
Month-over-month themes worth watching
1. Reference inflation on ChatGPT. Dictionary and definitional sites (Merriam-Webster, Cambridge, Dictionary.com, Collins, Wiktionary) surged in the latest ChatGPT snapshot. Models are leaning harder on clean lexical/reference evidence for certain query classes.
2. Video is platform-conditional. YouTube leads Perplexity and AI Overviews, places #2 on AI Mode, and ranks outside ChatGPT's top 15 by mention share. Video AEO is not optional for Google/Perplexity audiences — and not the main lever for ChatGPT.
3. Google citing Google. google.com at 11.5% in AI Mode (and 7.1% in AI Overviews) means profile completeness, product feeds, and entity consistency are citation infrastructure — not just local SEO hygiene.
4. Commerce and vertical review sites keep rotating. Automotive (Edmunds, KBB, Cars.com), retail (Walmart, Target, Amazon, Best Buy), and health (Healthline, WebMD, NIH) move in and out of top 20s month to month. Category-specific citation maps matter more than a universal top 10.
5. Volatility remains structural. Ahrefs notes AI Overviews have roughly a 70% chance of changing between observations. Citation half-life studies still put typical persistence in the weeks, not months. See AI Citation Volatility.
The long tail is still where most brands win
The giants dominate the leaderboard. They do not own every citation.
SurfacedBy's sample: 69.6% of cited domains appeared on exactly one engine. Geonimo's earlier 2.1M-citation analysis found 73.5% of citations outside the top 100 domains. Everything-PR still describes extreme concentration at the very top with a long democratic tail underneath.
You do not need to outrank Reddit. You need to be the clearest, most specific, most trusted page for the narrow prompts your buyers ask — so when an engine fans out past the mega-domains, it has something to grab.
That is also why earned media and third-party mention volume keep showing up as stronger predictors of brand mention than owned-domain polish alone.
What to do with the August map
- Pick engines by audience, then sources by engine. ChatGPT → Wikipedia, editorial, reference, Reddit. Perplexity / AI Overviews → YouTube + Reddit + reviews. AI Mode → Reddit + YouTube + Google-hosted surfaces. Claude → prestige editorial, docs, institutions.
- Treat Reddit and YouTube as infrastructure, not campaigns. Persistent, non-astroturfed presence in the communities and video formats your category actually cites.
- Audit google.com surfaces. Incomplete Business Profiles and product panels cost AI Mode visibility before a click is possible.
- Publish for the long tail. Narrow comparison, pricing, implementation, and "best X for Y" pages still earn citations the giants leave open.
- Measure share of voice on a fixed prompt set. Weekly, multi-engine, repeated runs — not a single screenshot of who ranked this Tuesday.
Obsurfable is built for that last step: define the Prompts that matter, see how ChatGPT and other engines answer them, and track whether you are mentioned or cited as the source map above keeps shifting.
Bottom line
As of August 2026, Reddit, YouTube, and Wikipedia still form the citation backbone — but mention share is wildly engine-specific. Reddit leads ChatGPT (16.7%) and AI Mode (19.9%). YouTube leads Perplexity (31.2%) and AI Overviews (21.1%) while barely registering on ChatGPT. google.com is now a top-3 AI Mode source. Claude mostly ignores the UGC layer entirely. The winning move is still platform-specific presence plus long-tail specificity — measured continuously, because this leaderboard moves on a monthly clock.
Primary figures from Ahrefs Brand Radar monthly most-cited tables (US, all topics; latest public snapshots labeled July 2026 and auto-updated monthly). Corroborated with SurfacedBy (127K citations), CiteMetrix (680M citations), Everything-PR AI Platform Citation Source Index, and related mid-2026 studies. Methodologies and denominators differ — treat percentages as directional within each study's definition of mention share.