I Drafted 200 Reddit Comments With AI Last Year — Here's What Got Flagged

I lost a Reddit account in February 2025. Not to a ban — to a single auto-removed comment that wiped out a year's worth of karma and got me flagged in three subs I cared about. The comment was a response to a small-business owner asking about email deliverability. It was helpful, polite, factually correct, and indistinguishable, line for line, from the kind of thing a thoughtful human would write. It was also 100% AI-generated, and a moderator in r/smallbusiness (who I later got to know) told me the post had been caught by a heuristic that flagged it within four minutes of submission.

The lesson was uncomfortable but worth a few hundred dollars in lost time: AI-generated comments on Reddit aren't detected because they're bad. They're detected because they are too good in the wrong ways — too smooth, too balanced, too willing to mention the same product the commenter just recommended the previous day. Reddit's anti-spam systems and the humans who run its busiest subs have spent the last 18 months training themselves to spot the AI-comments-by-default crowd. The pattern is learnable, and so is the way to draft with AI without getting tagged.

This is the workflow I now use for every AI-assisted comment. It works because it treats the model as a research and drafting assistant, never as the voice. The line is at the edit step. Everything before the edit is replaceable; everything after it is the comment.

The four tells that get AI comments flagged

Before I walk through the workflow, here are the four patterns that, in my experience and the experience of the moderators I asked, get AI comments auto-removed or reported. None of them are "the writing is bad." All of them are statistical tells.

Tell 1: The opening is too even-handed. "That's a great question, and there are a few different ways to think about this..." is the single most common AI-comment opener. Real Redditors almost never start that way. They start with a comma splice, a hot take, a personal anecdote ("I ran into this last year and..."), or just the answer. AI defaults to the polite academic register. Redditors default to the conversation register. The 200-millisecond feel of the opening sentence is what mods and AutoModerator key on.

Tell 2: The comment is the same shape every time. AI comments have a recognizable structure: brief acknowledgment of the question, one or two setup sentences, three to five bulleted points or a tidy paragraph pair, a polite sign-off. If a user has commented 30 times in a month and every comment has that shape, even if the content is good, the pattern is a flag. Real users have shape drift — long rambling replies some days, terse one-liners other days.

Tell 3: The product mention is too well-placed. This is the give-away that gets marketing-flagged comments removed even when the prose is fine. The pattern: someone asks about X, the AI-commenter explains X, then mentions "tools like [Product] can help" at exactly the right place. Real Redditors who recommend products do it sloppily. They name a competitor alongside it. They say "I use it but it's not for everyone." They add a caveat. The marketing-perfect product mention is what trips the report button.

Tell 4: The post is on-topic at the wrong level of detail. AI comments have a specific failure mode: they're calibrated for the question, not the thread. The original poster asks a casual question; the AI commenter responds with a textbook-grade answer. Real Redditors match the energy of the thread. If the question is "what's a good free option," the answer is "I use Trello for free, works for me." If the answer is "Let me walk you through the seven ways organizations evaluate project management platforms at scale," the comment is suspicious.

If you've spent time on Reddit, you can feel these tells without knowing how to name them. They are what makes a comment "feel off." The fix is not to make the AI write worse. The fix is to make sure AI only does the part it's good at.

The workflow: monitor, draft, edit, verify

The full process I run for each AI-assisted comment has four steps. The first three use AI. The last one is entirely human. If you skip step four, you ship AI-comments that read like AI-comments. If you skip steps one through three, you write everything by hand and you can't keep up with the volume that makes Reddit worth doing in the first place.

Step 1: Monitor the right threads. Reddit engagement dies when you try to cover too much ground. The accounts I run that survive long-term pick three to five subs and monitor them aggressively, not twenty subs and monitor them passively. The monitoring stack that has worked for me: GummySearch (paid, around $48/month, best for finding threads by keyword across many subs and tracking them over time) for the strategy view, then a private RSS feed pulling the new posts from each sub's top-of-day sort, refreshed hourly. I read the new posts in those subs every morning, fifteen minutes. Comments go where I've read the prior week. Comments do not go on day-one posts I found via a keyword alert.

This is the part AI cannot help with. The "is this thread worth engaging with" judgment is the highest-leverage decision in the workflow, and it's one of the things that makes an AI account look fake if it gets it wrong. Real Redditors know the inside jokes of their subs. They know who the regulars are. They know that a "what's the best X" thread on a Tuesday in r/sales is a different animal than the same thread on a Friday in r/sales. AI cannot develop this context fast enough, and trying to fake it produces the most-cringe AI comments of all — the ones that get into nuanced territory they obviously don't belong in.

Step 2: Draft the comment with AI using a research-first prompt. Once I've decided a thread is worth responding to, the AI does two things. It reads the original post plus the top three to five existing comments (so it doesn't repeat what was already said), and it drafts a comment that brings something new. The prompt that has worked for me, lightly edited per sub:

You are helping me draft a Reddit comment. Below is the original
post and the existing top 3-5 comments.

Original post: [paste]
Top comments: [paste]

Write a comment that:
- Brings a fact, example, or angle NOT in the existing top
  comments
- Matches the conversational tone of the thread (formal-casual
  subreddits: r/sales, r/SEO, r/marketing. Casual-casual:
  r/smallbusiness, r/sysadmin, r/freelance)
- Is between 60 and 220 words (this sub's median comment is
  ~110 words; longer than the median looks suspicious)
- Does NOT mention any product or service by name. I will add
  that myself only if relevant.

Output the comment only. No preamble.

Three things to notice. First, the prompt explicitly forbids product mentions — that's a guardrail for me, not for the model. The comment is drafted without the marketing ask, and I add the product mention (or not) on my own. Second, the word-count target is sub-specific. The median comment length in r/SEO is around 180 words; in r/smallbusiness it's about 90. AI defaults to ~250 words, which is longer than almost any sub's median and is a tell in itself. Third, the prompt asks for something not in the existing top comments. This is the "information gain" rule — the same one Google uses to rank blog content, and it works just as well on Reddit.

The output is a draft. Most of the time, it's 70% of the way there. That 70% saves me 15 minutes per comment, which is why the workflow is worth doing.

Step 3: The edit pass — this is the only step that matters. This is where I throw out or rebuild anything that smells like AI. The edit pass has six checks, and I run them every time:

1. Strip any sentence that opens with a transition ("Furthermore," "Additionally," "That said," "It's worth noting"). Real Redditors don't write these in casual replies.
2. Replace any general claim with a specific one. "Most teams struggle with this" → "I've had three clients in the last year run into this exact issue, and the pattern was..." Specifics are the AI's biggest weakness and the human's biggest advantage. If you can't make a claim specific, cut the claim.
3. Add one self-deprecating or messy detail. A typo I left in, a half-formed thought, an admission that I don't know something. The model never adds these. Real users do, and the asymmetry is the single biggest thing that separates flagged comments from upvoted ones.
4. Cut the conclusion sentence. AI loves a tidy wrap-up: "Hopefully that helps!" or "Let me know if you have questions!" These are pure AI tells on Reddit. Cut them. The comment ends on the substantive sentence, not the courtesy.
5. Check the product mention, if any, for sloppiness. If I do mention a product (this is rare — maybe one in fifteen comments), I do it badly on purpose. "I use [Product] but I've also heard good things about [Competitor]" is what a real recommendation looks like. "I highly recommend [Product] for anyone in this situation" is what gets you reported.
6. Read it aloud. This is the only AI-detection tool that consistently works, and it's free. If the comment sounds like a colleague wrote it because they were rushing, post it. If it sounds like a chatbot wrote it because it was being thorough, rewrite it.

I spend more time on the edit than on the draft. The 70%-draft-plus-edit pipeline averages 8 minutes per comment. A fully hand-written comment takes me 18 minutes. The AI cuts my time by more than half on comments I'd be writing anyway, and the edit step is what makes the comments survive.

Step 4: Verify and engage with replies. This is the part marketing teams routinely skip and is the reason most AI-Reddit strategies die. The comment lives or dies on what happens in the next 24 hours. If a real person replies asking a follow-up, I answer that follow-up with a hand-written reply, in voice, on the same account. If three people upvote and nobody replies, I don't add anything. If the comment gets downvoted, I take it down myself and post a brief apology comment, which is what a real Redditor who overshot would do.

The point of Reddit engagement is not "post comment, get link click." It's "be the person who is recognized in the sub as someone who shows up." The AI is the drafting tool. The recognition comes from the human follow-up.

The rule I think more people should know about

There's one line in this whole workflow that I want to be honest about, because most Reddit marketing content I read pretends it doesn't exist: most companies should not be doing AI-assisted Reddit engagement at all. It only works if the company is willing to invest the kind of human time that most marketing teams won't — the daily 15-minute lurk, the 8-minute edit per comment, the follow-up replies, the slow accumulation of sub-level credibility. If you're optimizing for a comment-to-link-click ratio, the math almost never works. If you're optimizing for long-term presence in a community that will, over years, become a meaningful channel for trust and inbound, the math can work — but only if you treat the AI as a tool and the human as the actual participant.

The accounts I run that have lasted longest on Reddit follow that rule. The ones that died are the ones where the AI was allowed to be the voice. There's no clever prompt or detector-dodging technique that fixes that. The model is the model. The human is the human. The choice is which one you want speaking for you.