Reddit in Google and AI Answers: Why the Numbers Disagree

The short answer

Reddit is one of the domains AI answers cite most, but there is no single number for how often. Three published analyses from 2025 put Reddit anywhere from outside the top ten to the leading source, depending on the assistant, the month and, above all, what was being counted. None of them is wrong on its own terms. They measured different things.

This post lays the three side by side, with their dates and methods, so you can tell which claim a headline is actually making. We add no numbers of our own.

Three studies, three sets of numbers

Profound (published 5 June 2025, updated August 2025). Profound's analysis covers ChatGPT, Google AI Overviews and Perplexity from August 2024 to June 2025, across what it calls a dataset of 680 million citations. It reports two metrics. By share of all citations, Reddit was 1.8% on ChatGPT, 2.2% on AI Overviews and 6.6% on Perplexity. By share within each platform's top ten cited sources, Reddit was 11.3%, 21.0% and 46.7%. Its headline reading:

“Reddit emerges as the leading source for both Google AI Overviews (2.2%) and Perplexity (6.6%).”

Ahrefs (published 11 June 2025). Ahrefs' study uses its Brand Radar data for the single month of June 2025: about 76.7 million AI Overviews, 957k ChatGPT prompts and 953.5k Perplexity prompts. Its metric, Mention Share, “measures how often the model chooses a domain.” On Reddit it says:

“Reddit and Quora rank high only in AI Overviews (7.4% & 3.6%). They don't crack the top-10 in ChatGPT or Perplexity.”

Semrush (published 10 November 2025). Semrush's three-month study took weekly snapshots from 14 July to 12 October 2025 for more than 230,000 prompts on ChatGPT search, Google AI Mode and Perplexity, looking each week at the 25 domains cited most often. It found Reddit among the top five cited domains on all three, and a sharp swing on ChatGPT:

“ChatGPT cited Reddit in close to 60% of prompt responses in early August before collapsing to around 10% by mid-September.”

Even after that drop, Semrush reports Reddit and Wikipedia were still ChatGPT's two most-cited domains as of October 2025.

Why the numbers disagree

Put next to each other, the studies clash most clearly on Perplexity and ChatGPT. Profound names Reddit Perplexity's leading source; Ahrefs, for June 2025, does not have it in Perplexity's top ten at all. Most of the gap is explained by four differences.

1. Different metrics. “Share of all citations” (Profound's 2.2%) and “share within the top ten sources” (Profound's 21.0%) describe the same data and differ roughly tenfold. Profound itself notes the top-ten figures “do not represent overall citation volume.” Semrush counts something else again: the share of responses that cite Reddit at least once. One answer can carry many links, so a domain can appear in a large share of answers while holding a small share of all links.
2. Different windows. Profound pools ten months, Ahrefs looks at one month, and Semrush tracks week by week. A pooled average hides the kind of swing Semrush recorded within a few weeks of August and September 2025.
3. Different products. Profound and Ahrefs measure Google AI Overviews. Semrush measures Google AI Mode. They are separate Google features, so a figure for one is not a figure for the other.
4. Different prompt sets. Each vendor runs its own prompts or tracked queries. Profound's page does not describe how its prompts were chosen. Which topics are in the set (product questions, health, local search) changes which domains come out on top.

The studies are also cautious about causes. On the ChatGPT drop, Semrush's Sergei Rogulin says: “Correlation doesn't always imply causation.” The study states its data does not show exactly why the shift happened.

What Google says, and what it does not

Google has not said that AI Overviews favour Reddit. Its Search Central page on AI features (last updated 10 December 2025) says:

“There are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary.”

The same page says both features may use a “query fan-out” technique, running several related searches across subtopics and data sources to build one response.

Google and Reddit do have a data deal. Google's 22 February 2024 announcement says Google gained access to Reddit's Data API, and that the partnership “does not change Google's use of publicly available, crawlable content for indexing, training, or display in Google products.” It says nothing about citation rates in AI answers.

Analysts disagree on what to infer. Ahrefs' author writes, “It seems Google favors user generated content sites.” Writing for Surfer, Joshua Hardwick says “we have no idea whether AIO citations somehow prioritise Reddit” and offers a simpler explanation: Reddit is huge and ranks in ordinary results for millions of queries. Both are opinions, not findings.

How to read the next Reddit citation stat

Before you repeat a Reddit citation figure, check five things:

• Which assistant: ChatGPT, Perplexity, AI Overviews, AI Mode, or a blend.
• What is counted: share of all citations, share of answers, or share within a top list.
• When: the exact months, and whether the data is pooled or tracked over time.
• Whose prompts: how many, on what topics, and whether the method is published.
• Who published it: all three studies above come from companies that sell search or AI visibility tools.

A figure without those five answers is not comparable to any other. And given how fast Semrush saw ChatGPT move in 2025, a figure more than a few months old may no longer describe today's answers.

What this means if you take part on Reddit

The studies agree on one thing: Reddit threads are a regular source for AI answers across several assistants. They do not show that any particular post will be cited.

If you take part in subreddits to be useful to the people there, Reddit's own rules still apply. As of 2026-10-16, Rule 2 of the Reddit Rules says, in part:

“Participate authentically in communities where you have a personal interest, and do not spam or engage in disruptive behaviors (including content manipulation) that interfere with Reddit communities.”

Posting as a fake stranger, staging conversations or buying accounts breaks these rules. Each subreddit adds its own rules on top, so read them before you post.

What this does not cover: how any assistant ranks sources internally, and any figure published after the studies above. It is not legal advice.

Agent Agency is software that learns your product from a link and runs AI agents that promote it in online communities.