The social platforms ChatGPT, Perplexity, AI Overviews, AI Mode, Gemini, and Copilot cited most in September 2026, week by week and by industry, and where Reddit and YouTube gained or lost against August.
Ask ChatGPT or Google a question and the answer often comes with a list of links, which are the pages the AI used to write its reply (also known as its citations). A lot of them point to social platforms, such as a Reddit thread where people explore community opinions or a YouTube review of a product.
That matters for how AI assesses your brand's reputation. When an AI engine leans on Reddit, what people say about you on Reddit shapes what the AI tells the next person who asks about you. When it leans on YouTube, your videos, and other people's videos about you, do the same job.
To see which platforms each engine relies on, we looked at the AI answers that cited at least one source between August 29 and September 27, 2026, across the questions Searchable customers track. They come from six engines: ChatGPT, Perplexity, Google's AI Overviews (the AI summary at the top of Google results), Google's AI Mode (its chat-style search), Gemini (Google's chatbot), and Microsoft Copilot. For each engine we counted the share of answers that cited Reddit, YouTube, LinkedIn, and other social platforms.
- ChatGPT's favorite is Reddit: its most cited social platform in every week of September, though it now cites Reddit in 5.9% of answers, down from 10.2% in August.
- Google's AI Overviews and AI Mode favor YouTube: both cited it most in every week of September, in 31.2% and 29.5% of answers. Gemini favors Reddit.
- Perplexity splits between Reddit and LinkedIn: Reddit led every week of September, but by less than a point each time. Copilot favors LinkedIn, though it rarely cites social platforms at all.
- Reddit fell on ChatGPT and AI Mode: both cited it less than in August, while Perplexity and Gemini cited it more.
- YouTube fell on AI Mode and slipped on AI Overviews: on ChatGPT it also slid within September, from 2.8% of answers in the first week to 1.3% in the last.
- Industry changes the mix: ChatGPT and Perplexity cite LinkedIn most for software, marketing, industrial, and legal questions, and Reddit most for consumer industries such as fashion, beauty, and sport. Google's AI Overviews cites YouTube most in almost every industry.
Share of each AI engine's answers that cite each social platform, September 2026
August 29 to September 27, 2026. Darker means cited more often. The outlined cell is the engine that cites each platform most. Hover over a logo or a square for detail.
| 2.2%YouTube on ChatGPT: 2.2% of answers | 2.6%YouTube on Perplexity: 2.6% of answers | 31.2%YouTube on AI Overviews: 31.2% of answers. The engine that cites it most | 29.5%YouTube on AI Mode: 29.5% of answers | 2.3%YouTube on Gemini: 2.3% of answers | 0.5%YouTube on Copilot: 0.5% of answers | |
| 5.9%Reddit on ChatGPT: 5.9% of answers | 11.3%Reddit on Perplexity: 11.3% of answers | 17.7%Reddit on AI Overviews: 17.7% of answers. The engine that cites it most | 16.5%Reddit on AI Mode: 16.5% of answers | 5.4%Reddit on Gemini: 5.4% of answers | <0.1%Reddit on Copilot: under 0.1% of answers | |
| 4.9%LinkedIn on ChatGPT: 4.9% of answers | 10.9%LinkedIn on Perplexity: 10.9% of answers. The engine that cites it most | 8.1%LinkedIn on AI Overviews: 8.1% of answers | 6.0%LinkedIn on AI Mode: 6.0% of answers | <0.1%LinkedIn on Gemini: under 0.1% of answers | 1.5%LinkedIn on Copilot: 1.5% of answers | |
| 0.8%Facebook on ChatGPT: 0.8% of answers | 0.3%Facebook on Perplexity: 0.3% of answers | 13.9%Facebook on AI Overviews: 13.9% of answers. The engine that cites it most | 10.7%Facebook on AI Mode: 10.7% of answers | 1.2%Facebook on Gemini: 1.2% of answers | 0.1%Facebook on Copilot: 0.1% of answers | |
| 0.4%Instagram on ChatGPT: 0.4% of answers | 0.4%Instagram on Perplexity: 0.4% of answers | 7.3%Instagram on AI Overviews: 7.3% of answers. The engine that cites it most | 4.8%Instagram on AI Mode: 4.8% of answers | <0.1%Instagram on Gemini: under 0.1% of answers | <0.1%Instagram on Copilot: under 0.1% of answers | |
| 0.2%TikTok on ChatGPT: 0.2% of answers | 0.3%TikTok on Perplexity: 0.3% of answers | 1.7%TikTok on AI Overviews: 1.7% of answers. The engine that cites it most | 1.2%TikTok on AI Mode: 1.2% of answers | <0.1%TikTok on Gemini: under 0.1% of answers | <0.1%TikTok on Copilot: under 0.1% of answers | |
| 0.2%Medium on ChatGPT: 0.2% of answers | 0.8%Medium on Perplexity: 0.8% of answers | 1.4%Medium on AI Overviews: 1.4% of answers. The engine that cites it most | 0.9%Medium on AI Mode: 0.9% of answers | 0.5%Medium on Gemini: 0.5% of answers | 0.1%Medium on Copilot: 0.1% of answers | |
| <0.1%Quora on ChatGPT: under 0.1% of answers | <0.1%Quora on Perplexity: under 0.1% of answers | 2.7%Quora on AI Overviews: 2.7% of answers. The engine that cites it most | 2.1%Quora on AI Mode: 2.1% of answers | 0.1%Quora on Gemini: 0.1% of answers | <0.1%Quora on Copilot: under 0.1% of answers | |
| 0.1%X on ChatGPT: 0.1% of answers | 0.4%X on Perplexity: 0.4% of answers. The engine that cites it most | 0.1%X on AI Overviews: 0.1% of answers | 0.2%X on AI Mode: 0.2% of answers | <0.1%X on Gemini: under 0.1% of answers | <0.1%X on Copilot: under 0.1% of answers |
Share of answers citing at least one page from the platform. Only engine and platform pairs whose citations are spread across many brands can be outlined.
Índice
Perplexity splits between Reddit and LinkedIn
Reddit was Perplexity's most cited social platform in every week of September, but LinkedIn was never more than a point behind. Across the month Reddit and LinkedIn were almost level, at 11.3% and 10.9% of answers.
How often each platform was Perplexity's most cited
Each square is one week, Monday to Sunday, for the weeks starting August 31 to September 21, 2026, shaded by the share of Perplexity answers citing the platform. The count on the right is the number of weeks each platform was the most cited. Hover over a square for detail.
How Perplexity's top platforms moved from June to September
Reddit rose from 6.4% to 11.0% and LinkedIn eased from 13.1% to 10.9%, leaving the two level.
How Perplexity's top social platforms moved
Share of Perplexity answers citing each platform, by week, weeks starting June 22 to September 14, 2026.
Reddit's gains and losses
Against August (July 30 to August 28), Reddit lost ground on ChatGPT and AI Mode and slipped on AI Overviews. ChatGPT's fall was the largest, from 10.2% of answers to 5.9%, much of it the mid-August step shown above. Reddit gained on Perplexity, from 9.4% to 11.3%, and on Gemini, from 3.6% to 5.4%.
Reddit's share of answers, July 30 to August 28 vs. August 29 to September 27, 2026
Share of each engine's answers citing at least one page from the platform.
| Engine | Jul 30 to Aug 28 | Aug 29 to Sep 27 | |
|---|---|---|---|
| 10.2% | 5.9% | ||
| 9.4% | 11.3% | ||
| 19.3% | 17.7% | ||
| 18.6% | 16.5% | ||
| 3.6% | 5.4% |
An up or down arrow means the rise or fall holds both across all tracked questions and across only the questions asked in both months; otherwise the line shows no clear change. AI Mode answers carried about half as many links from August 24, which pulls its figures down.
YouTube's gains and losses
Against August, YouTube's share of AI Mode answers fell from 37.0% to 29.5% and its share of AI Overviews answers slipped from 33.5% to 31.2%. On ChatGPT the monthly figure edged up, from 1.9% to 2.2%, but that hides a slide within the month: ChatGPT cited YouTube in 2.8% of answers in the first week of September and 1.3% in the last.
YouTube's share of answers, July 30 to August 28 vs. August 29 to September 27, 2026
Share of each engine's answers citing at least one page from the platform.
| Engine | Jul 30 to Aug 28 | Aug 29 to Sep 27 | |
|---|---|---|---|
| 1.9% | 2.2% | ||
| 33.5% | 31.2% | ||
| 37.0% | 29.5% | ||
| 2.2% | 2.3% |
An up or down arrow means the rise or fall holds both across all tracked questions and across only the questions asked in both months; otherwise the line shows no clear change. AI Mode answers carried about half as many links from August 24, which pulls its figures down.
Method: how we measured this
- Data: A Searchable analysis of citations by ChatGPT, Perplexity, Google AI Overviews, AI Mode, Gemini, and Copilot on questions tracked by Searchable customers. It describes what these engines cited for these questions, not market share.
- Windows: The heat table covers a 30 day period, August 29 to September 27, 2026, called September in this article. The weekly squares cover the four Monday to Sunday weeks from August 31 to September 27. Gains and losses compare that with the previous 30 days, July 30 to August 28, called August. The line charts cover the weeks from June 22 to September 20, and moves from June to September compare its first four weeks with its last four.
- Measure: The share of an engine's answers that cite at least one page from a platform. A site counts once per answer. A platform is an engine's most cited in a week when it has the highest share of that week's answers.
- Checks on every change: A rise or fall against August is only called when it holds both across all tracked questions and across only the questions asked in both months. Moves from June to September are only described when the questions tracked across the whole quarter move the same way.
- Questions section: Figures on brand mentions come from the same answers. Reddit upvotes, comments, age, and length were read on September 29 for a random sample of cited threads.
- Industries: Each brand is assigned one industry from its website and the topics it tracks. Industry figures are shown for ChatGPT, Perplexity, and AI Overviews separately. A platform is shown as an engine's most cited only when it also comes first with every brand weighted equally and with the brands citing it most set aside; otherwise the two leading platforms are shown as level. The differences named in the text pass the same checks.
- Brand concentration: A platform is only ranked or outlined for an engine when its citations are spread across many brands' questions rather than coming from a few.
See which platforms AI cites for your brand
Searchable shows which websites AI engines cite when your customers ask about your category, from Reddit threads to YouTube reviews, and tracks your brand across every engine.
- See which websites AI cites for your customers’ questions
- Find the social platforms that matter in your industry
- Track your brand across every major AI engine
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