Research · October 1, 2026
Does ChatGPT use Reddit as a source? What 3,600 AI answers show
400 Dutch-language questions without a brand name, 3 runs per chatbot, measured through the APIs of ChatGPT, Gemini, and Perplexity.
Matt Timmermans, Timmermans Media. Measured: September 26, 2026. Preregistration: doi.org/10.5281/zenodo.22974863. Data: doi.org/10.5281/zenodo.23010967.
Does ChatGPT use Reddit as a source? It finds Reddit often, but almost never cites it. In 552 of 1,200 ChatGPT answers (46%) to 400 Dutch-language questions, at least one Reddit page was among the sources found while searching. ChatGPT cited Reddit as a source exactly once, out of 3,527 citations.
So if you only count visible citations, you miss part of the sources ChatGPT comes across. Whether those sources influence the answer is not something this study established. The results apply to the APIs as they worked on September 26, 2026; the apps may behave differently.
Key figures
Reddit in ChatGPT, Gemini, and Perplexity: the key figures
of ChatGPT answers had Reddit among the sources it found
552 of 1,200 answers had at least one Reddit page among the sources ChatGPT found while searching.
of ChatGPT's 3,527 citations went to Reddit
As a visible source in the answer, Reddit appeared exactly once.
for buying questions, Reddit shows up far more often
Reddit was among the sources found in 61% of ChatGPT's commercial answers, versus 25% of informational ones.
times Gemini cited Reddit as a source
For commercial questions, Reddit ranks 7th in Gemini. Perplexity found not a single Reddit page.
In short: across 400 Dutch-language questions, each asked three times through the API, ChatGPT found a Reddit page while searching in 552 of 1,200 answers (46%), but cited Reddit only once in 3,527 citations. Measured September 26, 2026. Whether Reddit influences the answers was not measured.
The full study this publication is part of covers 6,120 answers. This publication uses the baseline measurement: 400 questions, 3 runs, 1,200 answers per chatbot.
Found versus cited
How often does ChatGPT find Reddit without citing it?
Very often. In 552 of 1,200 answers (46%), at least one Reddit page was among the sources ChatGPT found while searching. ChatGPT cited Reddit as a source exactly once. No other website was found by ChatGPT this often.
A chatbot that searches the web does two things. First it searches and gets back a list of sources. Then it writes an answer and decides which sources to list visibly. Through the API, ChatGPT returns both lists: the sources found while searching, and the sources shown with the answer. That let us compare, answer by answer, what ChatGPT found and what it then cited.
Found
In the methodology: retrieved. A URL the API reports as a source from a ChatGPT search. That does not mean ChatGPT opened or read the page. All Reddit mentions come from the source lists of searches.
Cited
Visibly listed with the answer, usually as a link or footnote. These are the only sources the user sees.
| Website | Found while searching | Cited in the answer |
|---|---|---|
| reddit.com | 552 of 1,200 (46%) | 1 of 1,200 (0.1%) |
| rijksoverheid.nl | 214 of 1,200 (18%) | 114 of 1,200 (10%) |
| consumentenbond.nl | 204 of 1,200 (17%) | 103 of 1,200 (9%) |
| wikipedia.org | 184 of 1,200 (15%) | 0 of 1,200 (0%) |
| anwb.nl | 143 of 1,200 (12%) | 97 of 1,200 (8%) |
| youtube.com | 98 of 1,200 (8%) | 2 of 1,200 (0.2%) |
Number of ChatGPT answers in which the website appears at least once, out of all 1,200 baseline answers. Unweighted, same denominator for both columns.
Figure 1. Number of ChatGPT answers in which the website appears at least once, as a share of all 1,200 baseline answers, unweighted and with the same denominator for both bars. Measured September 26, 2026. Conclusion: Reddit, Wikipedia, and YouTube are often found but almost never cited; government sites and consumer organizations do get cited.
In total, Reddit URLs appeared 6,165 times in ChatGPT's source lists. That count includes repeat mentions: it covers 3,493 distinct Reddit pages.
Wikipedia and YouTube show the same pattern. Wikipedia was among the sources found in 184 answers and was not cited once. YouTube was cited twice. Websites of government and institutions, by contrast, often do get cited when ChatGPT finds them: in 33% of cases, versus 22% for brands and online stores (exploratory).
Example: the landscaper in Utrecht
The only time ChatGPT cited Reddit as a source was for the question “I live in Utrecht. Who is the best landscaper?” (asked in Dutch). The answer first recommends a landscaping company and backs that up with its first place and high score in the Utrecht listing on Trustoo, a Dutch customer review platform. It then names, for a natural garden, a second landscaper that was “specifically recommended” by a resident on r/Utrecht, with a link to that thread. ChatGPT itself notes that this is a personal recommendation, not a comparative review.
Here Reddit did become visible: as support for a concrete recommendation. That is one case, not a pattern. But it does show the difference between three things that often get mixed up: a page found while searching, a page cited as a source, and a business that gets recommended.
Does ChatGPT search Reddit on purpose?
No. None of the 8,745 search queries ChatGPT ran in the baseline measurement contained the word Reddit or the search operator site:reddit.com. The Reddit pages came along in the regular search results.
Since May 2024, OpenAI has had a partnership with Reddit that gives it access to current Reddit content. Whether that is why Reddit shows up so often is something this data cannot establish.
Buying questions
Which questions surface Reddit in ChatGPT's search results?
Mainly buying questions. For commercial questions, Reddit was among the sources found in 61% of ChatGPT's answers (422 of 687); for informational questions, in 25% (130 of 513).
| Category | Commercial answers with Reddit found |
|---|---|
| Local service providers | 100% |
| Tech and electronics | 89% |
| Marketing | 89% |
| HR and staffing | 86% |
| Legal | 75% |
| Education and courses | 75% |
| Food and drink | 72% |
| Health and nutrition | 31% |
| Bookkeeping and accounting | 31% |
A selection of the highest and lowest categories. Share of ChatGPT's commercial baseline answers per category, unweighted. The numbers per category are small: the 100% for local service providers rests on 21 answers (7 questions).
Which subreddits does ChatGPT find?
Judging by their names, mostly subreddits about the Netherlands. A subreddit is a forum within Reddit devoted to a single topic. We could not measure the language of the pages themselves, because the found sources have no title.
| Subreddit | Times found | Number of answers |
|---|---|---|
| r/nederlands | 607 | 235 |
| r/Klussers | 260 | 43 |
| r/Offertes | 238 | 37 |
| r/thenetherlands | 204 | 131 |
| r/werkzaken | 177 | 60 |
| r/geldzaken | 166 | 74 |
| r/motorfietsen | 143 | 26 |
| r/ZZPNederland | 141 | 35 |
| r/FreelanceNL | 124 | 58 |
| r/EVMobiliteit | 115 | 20 |
Times found includes repeat mentions.
Per chatbot
Do Gemini and Perplexity use Reddit as a source?
Gemini does, on a small scale; Perplexity does not. Reddit plays a different role in each chatbot. In Gemini, Reddit is a small but visible source for buying questions. In Perplexity, Reddit does not appear at all.
Gemini
Gemini cited Reddit as a source 11 times, across 330 answers with sources (3.4%, weighted). Across all questions, Reddit ranks 45th of 1,062 cited websites, but for commercial questions it ranks 7th (5.9% of commercial answers with sources). All but one of the 11 citations come from commercial questions. Nine of them come from subreddits with a Dutch name, such as r/Utrecht, r/VeganNL, and r/EVMobiliteit, and two from r/Android. The API does not show which sources Gemini finds while searching.
Perplexity
Across 1,200 answers, Perplexity found not a single Reddit page, out of 10,440 search results found. At the top isConsumentenbond.nl (16.4% of the 692 answers with search results), followed by ANWB, Rijksoverheid, and Beslist.nl, a Dutch price comparison site. Through the API, Perplexity returns no citations with the answer.
| ChatGPT | Gemini | Perplexity | |
|---|---|---|---|
| Reddit found while searching | 552 of 1,200 answers | not visible through the API | 0 of 1,200 answers |
| Reddit cited as a source | once | 11 times | no citations through the API |
| Reddit's rank among cited websites | 399 of 685 | 45 of 1,062 (7 for buying questions) | n/a |
The cited websites
Which websites do ChatGPT and Gemini cite instead?
ChatGPT mainly cites government websites, consumer organizations, and brands' own websites. Gemini mainly cites brands and comparison sites. As a source in ChatGPT, Reddit is virtually absent; in Gemini it plays a small role, and only for buying questions.
| Rank | ChatGPT | Share | Gemini | Share |
|---|---|---|---|---|
| 1 | rijksoverheid.nl | 10.5% | consumentenbond.nl | 15.1% |
| 2 | anwb.nl | 7.8% | independer.nl | 13.6% |
| 3 | consumentenbond.nl | 7.5% | anwb.nl | 12.1% |
| 4 | voedingscentrum.nl | 6.8% | youtube.com | 9.7% |
| 5 | google.com | 6.3% | homedeal.nl | 8.2% |
| 6 | belastingdienst.nl | 5.4% | belastingdienst.nl | 6.8% |
| 7 | kvk.nl | 4.4% | rijksoverheid.nl | 6.3% |
| 8 | overheid.nl | 3.8% | overstappen.nl | 6.2% |
| 9 | thuisarts.nl | 2.8% | overheid.nl | 5.9% |
| 10 | ikea.com | 1.7% | werkspot.nl | 5.5% |
| ... | reddit.com (rank 399) | 0.1% | reddit.com (rank 45) | 3.4% |
Share of answers with at least one source in which the website appears as a source (ChatGPT: 1,115 answers, Gemini: 330). Weighted average across categories and question types. For Gemini, across 33 of the 40 combinations of category and question type, because Gemini gave no source at all in 7 combinations.
View the ranking as a chart, with 95% intervals
ChatGPT
Gemini
Figure 2. Top 10 cited websites per chatbot plus reddit.com, as a share of answers with at least one source (ChatGPT 1,115, Gemini 330), weighted across categories and question types, with 95% intervals. Measured September 26, 2026. Conclusion: for both chatbots, Reddit ranks far outside the top 10.
ChatGPT. Almost half (48%) of the 3,527 citations come from government and other institutions, such as Rijksoverheid (the Dutch central government), Belastingdienst (the Dutch tax authority), KVK (the Dutch Chamber of Commerce), Voedingscentrum (the Netherlands Nutrition Centre), and Thuisarts (a Dutch health information site run by family doctors). Consumentenbond (the Dutch consumer association) and ANWB (the Dutch motoring association) also fall into this group as consumer organizations; together they account for about a quarter of it. Another 44% comes from the websites of brands and online stores themselves. For commercial questions, such as “what is the best charging card for an electric car?”, Consumentenbond (12.9%) and ANWB (10.6%) top the list, as a share of commercial answers with sources. For informational questions, Rijksoverheid.nl is the largest source (14.0% of informational answers with sources).
That google.com ranks 5th looks odd. Of the 160 citations of google.com, spread across 64 answers, 102 went to developers.google.com and 48 to support.google.com: Google's own help pages, mainly for questions about marketing and software.
Gemini. Of the 2,897 citations, 47% come from brands and online stores and 27% from comparison sites, such as Independer, Overstappen.nl, Homedeal, and Werkspot. Government and institutions, including Consumentenbond and ANWB, account for 15%. For commercial questions, Gemini cites Consumentenbond in 29.4% of answers with sources, the highest citation score for any single website in the entire study.
ChatGPT also cites a small circle of websites far more often than the rest: the ten most-cited websites together account for 37% of all citations. In Gemini that figure is 16%.
Figure 3. Split of all citations by source type, per chatbot (ChatGPT 3,527, Gemini 2,897 citations). Other is a catch-all for small types, such as review platforms and unclassified Tweakers pages. Measured September 26, 2026. Conclusion: forums and user-generated content are virtually absent as a source in ChatGPT; in Gemini they make up a small share, mainly for buying questions.
Do ChatGPT and Gemini cite comparison sites more often than forums?
In this measurement, yes. For commercial questions, 7 in 10 Gemini answers with sources (69.8%) included a comparison site, versus 8.1% that included a forum or user-generated content. In ChatGPT the figures are 12.4% versus 0.2%; ChatGPT more often points directly to brands and to Consumentenbond and ANWB.
| Source type for commercial questions | ChatGPT | Gemini |
|---|---|---|
| Comparison or affiliate site (e.g., Independer, Kieskeurig) | 12.4% | 69.8% |
| Forums and user-generated content (e.g., Reddit, Tweakers forum) | 0.2% | 8.1% |
| Difference (95% interval) | 12.1 percentage points (9.0 to 15.3) | 61.7 percentage points (54.9 to 68.0) |
Share of commercial answers with sources in which at least one website of that type appears (ChatGPT 687 answers, Gemini 239). For Gemini, the Care and wellbeing category is missing, because Gemini gave no source there for commercial questions. Source types were assigned per website by a language model; see the study design.
Review platforms barely appear: in Gemini, Trustpilot shows up in 0.9% of answers with sources and Klantenvertellen (a Dutch review platform) in 0.6%; in ChatGPT, only Zorgkaart Nederland (a Dutch healthcare review site) appears, once. YouTube ranks 4th in Gemini (9.7%, 30 mentions); in ChatGPT it appears twice. Facebook is cited 22 times by Gemini and never by ChatGPT. Tweakers, a Dutch tech site, is cited 18 times by ChatGPT and 26 times by Gemini, mostly its Pricewatch and buying guides.
Is Reddit the most-cited source?
No. For ChatGPT, this was confirmed with a preregistered test. We compared Reddit with one preselected competitor per chatbot: google.com for ChatGPT and consumentenbond.nl for Gemini. If the competitor is demonstrably cited more often, Reddit is not No. 1.
| Chatbot | Competitor | Competitor as source | Reddit as source | Difference (95% interval) | Outcome |
|---|---|---|---|---|---|
| ChatGPT | google.com | 6.3% | 0.1% | 6.1 percentage points (4.7 to 7.7) | Confirmed |
| Gemini | consumentenbond.nl | 15.1% | 3.4% | 11.7 percentage points (7.7 to 15.4) | Inconclusive due to insufficient coverage |
Share of answers with at least one source. Weighted average across categories and question types.
For Gemini, the numbers point the same way, but the test could not formally be run. Gemini listed sources in only 330 of 1,200 answers (27.5%), and in 7 of the 40 combinations of category and question type, Gemini gave no source at all. The test rules are described in the study design.
Earlier studies
Why do other studies find more Reddit citations?
We cannot say for sure. Our result (0.1% for ChatGPT) is far below the figures from large American studies. But those were done with different questions, different models, sometimes through the apps, at a different time, and with a different metric. So this is not a direct comparison between countries.
Profound analyzed 680 million citations between August 2024 and June 2025 and found Reddit to be the largest source in Perplexity (6.6% of citations) and Google AI Overviews (2.2%). In ChatGPT it was 1.8%. Semrush tracked 230,000 prompts for thirteen weeks in 2025 and saw ChatGPT cite Reddit in nearly 60% of answers in early August. By mid September that had dropped to about 10%. In early 2026, several studies reported that YouTube had overtaken Reddit as the most-cited social platform.
In April 2026, Ahrefs analyzed 1.4 million ChatGPT prompts. Pages from a separate Reddit source were often retrieved but cited only 1.93% of the time. In mid-August 2026, Promptwatch reported that Reddit's share of ChatGPT Search citations fell from an average of 3.8% (July 18 to August 7) to 0.52% (August 14 to 17), an 86.4% relative drop. Promptwatch itself calls the size of that drop provisional. Our measurement on September 26 came after it: ChatGPT still found Reddit among its sources in 46% of answers, but cited it once in 3,527 citations.
Several explanations are possible. We did not test them, so read them as hypotheses:
Dutch-language questions and a Dutch location. Reddit has far less Dutch-language than English-language content. Of ChatGPT's sources whose title language could be determined, 76% had a Dutch title.
Questions without a brand name. We only asked general questions. Studies with brand or product questions may give a different picture.
API instead of the app. We measured through the API. The ChatGPT app may have different settings.
The timing of the measurement. The Semrush figures show how quickly citation behavior can change. Our measurement is a snapshot from September 26, 2026.
A different metric. Profound measures the share of all citations, Semrush the share of answers, and we the share of answers with sources. So these figures are not directly comparable.
Measuring visibility
What does this mean for measuring AI visibility?
Assess Reddit per chatbot and per measurement goal. A page found while searching, a visible citation, and a brand that gets mentioned each tell you something different about your visibility in AI.
Found, cited, and mentioned are three different things.
In this measurement, Reddit almost never produced a visible citation in ChatGPT. That says nothing about whether Reddit influences brand mentions, recommendations, or revenue; we did not measure that.
| Work | What this study adds |
|---|---|
| Reports on AI visibility | State separately whether a website appears while searching, gets cited as a source, or gets mentioned as a brand. Do not conclude from missing citations that a site was absent during the search. |
| Choosing platforms for content and PR | First check which sources appear for relevant buying questions, in the specific chatbot. The rankings in this study are an average across 20 industries: a starting point, not a universal priority list. |
| Advice on investing in Reddit | Make explicit which outcome you are after. Within this study design, this study offers little support for Reddit as a route to visible citations in ChatGPT. It does not establish what Reddit does for brand mentions, recommendations, or revenue. |
In practice:
Find out which websites get cited for questions about your industry, per chatbot. In this measurement, those were mainly government, consumer organizations, and brand websites in ChatGPT, and mainly brands and comparison sites in Gemini.
Check that the information about your business on those websites is correct, and on your own website. Brands and online stores account for 44% of all citations in ChatGPT and 47% in Gemini.
Assess Reddit separately on visible citations and on presence while searching. ChatGPT found Reddit in 61% of answers to buying questions, so what is said there about your industry often comes up.
When you get an AI visibility report, ask what is being measured: citations or found sources. That difference decides whether Reddit ends up at the top or the bottom.
Whether a mention on a particular platform is more effective than a Reddit thread is something we did not study. That would require research into the effect of such a mention.
SEO and GEO
What does this mean for your website's SEO and GEO?
Do not put everything on one platform. Each chatbot cites different kinds of websites, and in this measurement Reddit almost never produced a visible citation in ChatGPT.
GEO advice often names Reddit as the place your brand needs to be in order to show up in AI answers. That advice leans mainly on American studies in which Reddit was cited a lot. We do not see that in this Dutch measurement: ChatGPT often found Reddit, but cited it once. In Gemini, Reddit does play a small role for buying questions.
What does stand out is how differently the chatbots source their answers. That argues for spreading your efforts:
Your own website.
Brands and online stores account for 44% of all citations in ChatGPT and 47% in Gemini. Clear, current information about your services, prices, and terms on your own site remains the foundation.
Comparison sites and review platforms in your industry.
In Gemini, 69.8% of commercial answers with sources include a comparison site. In the landscaper example, the first recommendation was backed up with a score on Trustoo.
Authoritative sources on your topic.
For informational questions, ChatGPT mainly cites government and consumer organizations. Make sure what you write about your field is consistent with them.
Reddit as one channel among several.
ChatGPT found Reddit in 61% of answers to buying questions, and in Gemini Reddit ranks 7th for buying questions. So what is said there about your industry does come up. But as the only route to a citation in ChatGPT, this measurement offers little support for it.
Which of these routes delivers the most for brand mentions, recommendations, or revenue is something we did not measure. So for your own industry, look at which sources keep coming back for relevant buying questions, per chatbot and with repeated questions, and after making a change, measure again to see whether it made a difference.
Whether small websites stand a chance as a source next to big names is covered in our study of the Google traffic of AI sources. Whether an llms.txt file helps is covered in our study of llms.txt among AI sources.
Methodology
Study design: comparing found and cited sources
We specified the research questions, hypotheses, measurement settings, and analysis rules and deposited them publicly on Zenodo before the measurement began (DOI 10.5281/zenodo.22974863). A preregistration prevents you from adjusting the questions or the analysis to fit the outcome after the fact.
Hypotheses, definitions, test, settings, weights, and limitations
Preregistered hypotheses and amendments
After the deposit, two rules were amended on September 26, 2026, both before any analysis had been done: fetching a second page of Google results for 88 search terms (amendment 1) and the classification of websites for which the domain data source used gives no rank but does give traffic (amendment 2). This publication uses only the chatbots' answers, citations, and found sources, not Google search results or external domain data, so the amendments do not affect these figures. Both are recorded in the amendment log in the data deposit.
| Hypothesis | Content | Type | Outcome or estimate |
|---|---|---|---|
| H8a | Reddit is not the No. 1 cited website in either ChatGPT or Gemini | Primary | ChatGPT confirmedGemini inconclusive due to insufficient coverage |
| H8b | Reddit appears in fewer than 25% of answers with sources | Secondary | ChatGPT 0.1%, Gemini 3.4% |
| H8c | For commercial questions, comparison sites appear more often than forums | Secondary | ChatGPT +12.1, Gemini +61.7 percentage points |
Only the primary hypothesis gets an outcome label. We report secondary hypotheses as an estimate with an interval. The ranking of cited websites per chatbot is part of the preregistered reporting for H8a. All other figures outside H8a, H8b, and H8c are exploratory. The figures on ChatGPT's search queries, the breakdown of found Reddit pages by question type and category, the found versus cited comparison with the same denominator, the google.com citations by subdomain, and the landscaper example were added afterward (supplementary, not preregistered).
What counts as found and as cited
For an answer with search, the OpenAI Responses API returns two kinds of data: the sources returned by each search action, and the sources shown visibly with the answer (citations). In the analysis scripts the first group is called “retrieved” (“opgehaald”); in this publication we call it “found while searching.” Of all 51,054 retrieved sources from ChatGPT, 50,600 came from the source lists of search actions and 454 from pages ChatGPT explicitly opened (open_page). All 6,165 Reddit mentions belong to the first group: URLs the API reports as a source of a search action, without it being established that ChatGPT opened or read the page. They cover 3,493 distinct Reddit pages.
The test: Reddit versus one preselected competitor
To make H8a testable, we compare Reddit with one preselected competitor per chatbot. We chose that competitor based on a pilot run of 600 answers on September 25, 2026, one day before the main measurement: google.com for ChatGPT, consumentenbond.nl for Gemini. If the competitor is demonstrably cited more often than Reddit, Reddit is not No. 1.
For ChatGPT, the corrected p-value is 0.001, well below the preset threshold of 0.05. For Gemini, the preregistration stipulates that the test may not be run across the full benchmark if any combination of category and question type contains no source at all. That was the case for 7 of the 40 combinations. In addition, the choice of Consumentenbond as the competitor rests on only 10 questions with sources from the pilot run.
Questions, chatbots, and settings
| Questions | 400 Dutch-language questions without a brand name, 20 per category, spread across 20 consumer, business, and local categories. 229 commercial, 171 informational |
|---|---|
| Selection | Derived from Dutch keywords with search volume, drawn with a fixed random seed |
| Chatbots | ChatGPT (gpt-6-sol, OpenAI Responses API with web_search, location Netherlands), Gemini (gemini-3.8-flash, Gemini API with Google Search), Perplexity (sonar, Agent API with web_search, location Netherlands) |
| Settings | No system prompt, default settings, each question in a new session |
| Runs | 3 per question per chatbot: 1,200 answers per chatbot in the baseline measurement (6,120 answers in the full study) |
| Measured | September 26, 2026 |
Weights and intervals
For the preregistered measures, we first average over the three runs per question. We then average per category and question type, giving every category and both question types equal weight. That way a category with many sources does not count more heavily than one with few. Those weighted figures appear in the ranking and test tables. Unweighted shares, such as 552 of 1,200 answers, are always shown with their counts. Weighted, the share of answers with Reddit among the found sources is 42.9%.
The intervals come from a bootstrap: we resample questions 2,000 times within each category and question type and look at how much the outcome fluctuates. Because we test the hypothesis for two chatbots, we correct the p-values with the Holm method. That correction reduces the chance that one of the two tests comes out positive by chance.
Classifying websites by source type
Every source was reduced to its main domain, such as consumentenbond.nl. The type of website (government, brand, comparison site, forum, and so on) was determined by the language model Claude Sonnet 5, with a fixed instruction. The 200 most-cited websites were also classified by Claude Opus 5.5. The two agreed in 94.5% of cases; where they differed, the Opus label counted. Before the measurement, this approach reached 92% agreement on 200 test domains.
For Tweakers, Reddit, and YouTube, the classification was fixed in advance. Tweakers was split by section: Pricewatch as a comparison site, reviews and news as media, and the forum as user-generated content. Tweakers pages outside that fixed classification, such as the buying guides, were not classified afterward. They count as “unclassified” (7 citations in ChatGPT and 17 in Gemini for commercial questions).
Limitations of the Reddit study
- API, not the apps. The results apply to the API settings we tested. The ChatGPT app, the Gemini app, and Perplexity.ai may work differently.
- Gemini searches little. Gemini listed sources in only 330 of 1,200 answers (27.5%). As a result, the main test could not formally be run for Gemini.
- Perplexity returns no citations through the API. For Perplexity, we only look at search results found.
- Found is not read or used. A URL appearing among the search results does not mean ChatGPT opened the page or that its content ended up in the answer.
- No effect measurement. We measure which sources appear, not whether a mention on a platform leads to more citations, recommendations, or revenue.
- No human check of the source types. The classification was done by two language models from the same maker. Shared errors cannot be ruled out.
- A single point in time. The citation behavior of AI systems changes fast. This is the state of play on September 26, 2026.
- Model versions. The model names carry no date. A silent update by the provider would not be visible in the data.
Open data
Data deposit and citation for this Reddit study
The preregistration (10.5281/zenodo.22974863) and the data deposit (10.5281/zenodo.23010967) are on Zenodo. The answers, citations, found sources, and analysis scripts are in the data deposit. The data are licensed under CC BY 4.0, the analysis scripts under MIT.
Preregistration and data on Zenodo
The data deposit contains the answers, citations, found sources, analysis scripts, and the amendment log. The preregistration records the questions, hypotheses, and analysis rules as they stood before the measurement.
Cite this study
Timmermans, M. (2026). Does ChatGPT use Reddit as a source? What 3,600 AI answers show. Timmermans Media. Preregistration: doi.org/10.5281/zenodo.22974863. Data: doi.org/10.5281/zenodo.23010967. License CC BY 4.0. timmermansmedia.com/research/reddit-ai-sources/
This study is available under the CC BY 4.0 license.
Frequently asked questions
Frequently asked questions about Reddit as an AI source
Does ChatGPT use Reddit as a source?
ChatGPT finds Reddit often, but rarely cites it. Across 400 Dutch-language questions, each asked three times through the API, a Reddit page was among the sources ChatGPT found in 552 of 1,200 answers (46%). ChatGPT cited Reddit only once in 3,527 citations. Gemini cited Reddit 11 times; Perplexity found not a single Reddit page. Whether Reddit influences the answers was not measured.
What is the difference between a found source and a cited source?
A found source is a URL the API returns as the result of a ChatGPT search. That does not mean ChatGPT opened or read the page; not one of the Reddit pages was opened individually. A cited source is a page ChatGPT visibly lists with its answer. Only the latter is what the user sees. That is why we measure visibility by citations and report found sources separately.
Why are there no citations from Perplexity?
Without an extra instruction, Perplexity's Agent API does not return citations with the answer. In the pilot run, not one of the 200 answers included a source reference. The API does show which search results were found. We use those as a separate, exploratory measure.
Should my business stop using Reddit?
That does not follow from this study. It shows that in this measurement Reddit rarely produced a visible citation in ChatGPT. Whether a presence on Reddit contributes to brand mentions, recommendations, or revenue is something we did not measure.
Does this also apply to the ChatGPT app?
We cannot say for sure. We measured through the API with search turned on and the location set to the Netherlands. The app may use different default settings. The results apply to the configuration we tested.
What about Google AI Overviews?
We did not study Google AI Overviews, the AI summaries at the top of Google's results. American studies do find a lot of Reddit there. Whether the same holds in the Netherlands is an open question.
Can you measure which sources AI uses in my industry?
Yes. With the same study design we can measure, per industry, which websites ChatGPT, Gemini, and Perplexity use as sources, and whether your business is among them. See our GEO service.
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This page is the English edition of a study first published in Dutch. Read the original Dutch version.
Glossary
Dutch terms on this page
The study used Dutch questions and Dutch websites. These are the Dutch names and words that come up.
- ANWB
- Dutch motoring and travel association with roadside assistance and consumer advice, comparable to AAA.
- Belastingdienst
- Dutch tax authority, comparable to the IRS.
- Beslist.nl
- Dutch price comparison site for consumer products; beslist means “definitely.”
- Consumentenbond
- Dutch consumer association that tests products and services, comparable to Consumer Reports.
- Homedeal
- Dutch comparison site for energy, internet, and TV subscriptions.
- Independer
- Dutch comparison site for insurance, mortgages, and energy, comparable to NerdWallet.
- Kieskeurig
- Dutch product comparison and review site; the name means “choosy.”
- Klantenvertellen
- Dutch review platform for verified customer reviews; the name means “customers tell.”
- KVK
- Dutch Chamber of Commerce (Kamer van Koophandel), where every business registers.
- opgehaald
- Dutch for “retrieved.”
- Overheid.nl
- Dutch government portal for laws, regulations, and official publications.
- Overstappen.nl
- Dutch comparison site for switching energy, internet, and insurance; overstappen means “to switch.”
- r/geldzaken
- Dutch subreddit on personal finance; the name means “money matters.”
- r/Klussers
- Dutch subreddit on home repair and DIY; the name means “handymen.”
- r/motorfietsen
- Dutch subreddit for motorcycle riders; the name means “motorcycles.”
- r/nederlands
- Dutch-language general discussion subreddit; the name means “Dutch.”
- r/Offertes
- Dutch subreddit for comparing contractor quotes; the name means “quotes.”
- r/werkzaken
- Dutch subreddit on jobs and employment; the name means “work matters.”
- r/ZZPNederland
- Dutch subreddit for freelancers; ZZP stands for zelfstandige zonder personeel (“self-employed without staff”).
- Rijksoverheid
- Dutch central government's website for rules and public services, comparable to USA.gov.
- Thuisarts
- Dutch health information site written by family doctors; the name means “home doctor.”
- Trustoo
- Dutch review platform for local service providers, comparable to Yelp.
- Tweakers
- Dutch technology news and review site with a price comparison tool and a large forum.
- Voedingscentrum
- Netherlands Nutrition Centre, a government-funded source of official healthy eating advice.
- Werkspot
- Dutch marketplace that connects homeowners with tradespeople, comparable to Angi or Thumbtack.
- Zorgkaart Nederland
- Dutch review site where patients rate doctors, hospitals, and other care providers.
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