Is AI-written text on Reddit spread across everyone, or concentrated in a small set of accounts and communities?

This explores who is actually posting the AI-written text on Reddit: whether it comes from a few heavy users or is spread across many. The short answer is that the collection doesn't give an exact number. A study of 51 subreddits found that machine-generated text is concentrated in a small fraction of users, and in technical and help-seeking communities rather than spread across the platform How much machine-generated text actually appears on Reddit?. That study's headline figure of 9% is one detector's flagging rate in certain communities and months. It is not a platform-wide share, and it is not a count of users. If you want a precise percentage of accounts, the corpus doesn't have one.

The more surprising point is why Reddit looks so human in the first place. Most of Reddit is replies, and replies are almost entirely human. In one dataset, replies made up 72% of the scanned items and 98.1% of them were human-written. Top-level posts were 11.6% AI-generated, about five times the rate for replies even after accounting for length Why does Reddit's AI share seem so low compared to others?. So Reddit's low overall AI share of 4.4% partly reflects what kind of writing dominates the site. People still write their own replies in a conversation. Writing the post that opens a thread is where AI help shows up. A 'small fraction of users' and 'a format that invites AI' are two views of the same pattern: AI text clusters wherever writing feels like producing content rather than talking.

That is also why Reddit stands apart from other sites. The same kind of detector that saw AI-attributed posts on Medium and Quora jump from about 2% to about 38% between 2022 and late 2024 saw Reddit rise only from 1.31% to 2.45% Is AI-generated content rising faster on some platforms?. On the wider web, about a third of new websites were AI-generated or AI-assisted by mid-2025 How much of the internet is AI-generated now?. Places built around essays and articles absorbed AI quickly. Reddit's conversational threads mostly didn't.

A small group of posters doesn't mean a small effect. On Reddit, machine-generated comments, with their polite assistant-style warmth, got about as much engagement as human comments, and sometimes more Does machine-generated text get penalized in online engagement?. On a Chinese short-video platform, AI creators matched human creators' total engagement by posting more, even though viewers preferred the human videos Can AI creators match human creators through posting volume alone?. Put together, a few high-volume accounts can have an outsized presence. And because people spot AI content at roughly chance accuracy Can people reliably spot content made by AI?, every number here comes from automated detectors. Readers themselves usually can't tell.