Key takeaways
You can't prove it from the text. Every sign below also shows up in human writing. Treat them as hints, and look for several at once.
Specifics beat style. A post with no names, numbers or real moments is a stronger sign than any em dash.
The best test is the person. If a post doesn't match how someone writes their comments, their older posts or how they talk, that tells you more than any detector.
Detectors are unreliable on short posts. OpenAI withdrew its own AI classifier in 2023 for "its low rate of accuracy", and a Stanford study found detectors biased against non-native English writers.
LinkedIn draws the line at slop, not AI. Its "Seems like AI slop" button got over 1 million clicks in three weeks, and LinkedIn says copy-pasted AI posts now get about 40% fewer views. Using AI to help you write is still allowed.
To spot an AI-written LinkedIn post, look for a cluster of signs rather than one: a reveal-style hook, a "not X, it's Y" flip, lists of three, identical one-line paragraphs, stock words, and above all no specifics, no real opinion and no match with how the person usually writes. None of these proves anything alone, and AI detectors are unreliable on short posts, so judge the post, not the tool.
You've seen the post. It starts with "Here's what nobody tells you about leadership." It has five lines with an emoji each. It ends with "Agree?" You can't say exactly why, but it reads like nobody wrote it.
That instinct is often right. It's also often wrong, which is why this guide does two things: lists the 12 signs people use, and says honestly what each one proves.
Why "is this AI?" is hard to answer
The model that writes these posts learned from human writing. Every habit it has, it got from people. So every sign of AI writing is also a sign of some human's writing.
That's why detectors struggle, and why the better question is usually not "was AI involved?" but "did a person put anything of themselves into this?" LinkedIn, as you'll see below, asks the same question.
The 12 signs

Illustrative example, written for this guide.
The shape
1. A hook that promises a reveal. "Here's what nobody tells you." "Let me explain." "This changed everything." The first line sells a secret before the post has one.
2. The flip. "It's not about X. It's about Y." "That's not failure. That's feedback." One flip is a writing choice. A post built from three of them is a pattern.
3. Lists of three. "Faster, smarter, better." Three adjectives, three bullets, three lessons. Models lean on threes, like a lot of the writing they learned from.
4. A metronome rhythm. Every paragraph is one sentence. Every line is about the same length. Read it aloud and it ticks.
5. Emoji and bold as decoration. ✅ before every line, 🚀 at the end, a bold header over a two-line section. Formatting that organises nothing.
The words
6. The house vocabulary. "Delve", "landscape", "game-changer", "unlock", "elevate", "in today's fast-paced world", "a testament to". None is wrong. Several in one post is a signal.
7. Em dashes everywhere. The best known tell, and the weakest. Plenty of good writers use dashes; our piece on the em dash as an AI tell covers why it became one. Count it only alongside other signs.
The substance
8. No specifics. No name, no number, no date, no place, no cost. Take out the buzzwords and nothing is left. This is the strongest sign in the text itself, because specifics are the one thing a model can't invent truthfully.
9. No stance. The post weighs both sides and lands on "it depends" or "balance is key". A person posting usually has a view; that's why they posted.
10. A tidy moral, then "Agree?" The last line sums up what you just read, then asks for a reaction it doesn't need: "Agree?", "Thoughts?", "Let me know in the comments 👇".
The person
11. It doesn't match them. The post is polished; their comments are short and blunt. The post is about "authentic leadership"; their last year of posts was about shipping software. This is the most useful sign of all, and no detector can check it.
12. The comments read the same way. "Great insights! Thanks for sharing." under every post they comment on. A sudden jump from two posts a year to a long, polished post every day. AI often shows up in the pattern, not the single post.
What each sign proves

Illustrative example, written for this guide.
Not all signs are equal. Here's how much weight each group deserves:
Signs | How often humans do it too | Weight on its own |
|---|---|---|
1 to 7: shape and words | Often: these are taught in copywriting courses | Weak |
8 to 10: no specifics, no stance, tidy moral | Sometimes: mostly in rushed or corporate posts | Medium |
11 to 12: doesn't match the person | Rarely | Strong |
Two practical rules:
Count clusters, not single signs. A post with an em dash proves nothing. A post with a reveal hook, three flips, no specifics and "Agree?" is a different thing.
Check the person before the post. Thirty seconds on their profile (older posts, their comments) beats any amount of staring at one post.
A 60-second check
Read the first line. Does it promise a secret, or say something?
Look for one specific. A name, a number, a date, a place. None? Note it.
Find the opinion. Could you disagree with this post? If there's nothing to disagree with, note it.
Open their profile. Do their comments and older posts read the same way?
Count. Two or three notes plus a mismatch: probably AI, lightly edited or not at all. One note: probably a person having an average day.
Why detectors get it wrong

Source: OpenAI, January and July 2023.
Pasting a post into an AI detector feels more objective than counting signs. On a LinkedIn post, it usually isn't.
OpenAI gave up on its own detector. In OpenAI's evaluation, its classifier caught 26% of AI-written text and wrongly labelled human writing as AI 9% of the time. It said reliability "typically improves as the length of the input text increases", and LinkedIn posts are short. On 20 July 2023 OpenAI withdrew it "due to its low rate of accuracy".
Detectors flag non-native writers. A Stanford study titled "GPT detectors are biased against non-native English writers" found they consistently misclassify non-native English writing as AI-generated. On a global network like LinkedIn, that's a lot of innocent people.
Edited AI text slips through, and human text gets caught. In our comparison of five paid detectors, every vendor claims 98 to 99.9% accuracy, and every one struggles with edited AI text and misfires on some human writing.
A detector score is one more hint, not a verdict. Never accuse someone, or turn down a candidate, because a tool said "87% AI".
What LinkedIn does about AI posts

Menu shown as an illustration; the option launched at the end of July 2026.
LinkedIn doesn't label AI posts, and it doesn't ban AI. Its rule is: "It's ok to use AI to help you write, but your posts and comments need to represent your voice and your perspectives."
What it does fight is slop. At the end of July 2026 it added "Seems like AI slop" to the three-dot menu on every post and comment. LinkedIn's chief product officer, Hari Srinivasan, explained it like this: "Slop is hard to define and the definition changes; this lets us tune our models and make better feeds."
Three weeks later, The Register reported:
Over 1 million clicks on the button since launch.
About 40% fewer views for people who copy-paste AI-written posts, compared with before the button. That's LinkedIn's own figure, not an independent measurement.
No single report decides reach. One flag doesn't sink a post.
A private notice for authors when readers flag their posts, which LinkedIn says it's testing.
The line LinkedIn draws is the same one this guide draws: AI help is fine, an empty post isn't.
Should you report it?
Report slop, not suspicion. If a post has nothing in it (no specifics, no view, no person) and you'd rather see less of it, the button is there for that. If a post is useful and you just suspect a model helped, leave it. LinkedIn allows that, and you might be wrong.
Comments are a better place to push back than reports. "What happened next?" or "What number moved?" is a fair question to ask any post, and a real author can answer it.
If you use AI to write your own posts
Most people reading this guide also write with AI sometimes. The same signs tell you how not to be the post someone flags:
Add one specific nobody else has. A number from your week, a name, what it cost.
Pick a side. Say what you think, and why.
Cut the shape. Delete the reveal hook, the third flip and the "Agree?".
Write like your comments. If your comments are blunt, your posts can be too.
Our free LinkedIn AI post detector checks a draft for 50 LinkedIn-specific tells, gives each one a human swap and scores the post from 0 to 100, with no sign-up. For the full method, see how to write a LinkedIn post, and if ChatGPT is your drafting tool, how to make ChatGPT write like you.
Using AI on your own posts? Here is how to stop AI making things up in your posts.
Where VoiceMoat fits
VoiceMoat is an AI social media tool for LinkedIn and Twitter, built around sign 11. audenAI, the brain inside VoiceMoat, learns from your own published posts, so drafts start from how you already write, not from the house style. Every draft gets a Voice Match score against your real posts before you post it.
It won't make a post "undetectable", and that's not the goal. The goal is a post that's yours: your specifics, your view, your way of saying it. Try VoiceMoat free.
Frequently asked questions
Can you prove a LinkedIn post was written by AI?
No. Every sign of AI writing also appears in human writing, and detectors are unreliable on short posts. You can only judge how likely it is, from a cluster of signs and a mismatch with how the person usually writes.
Are AI detectors accurate on LinkedIn posts?
Not reliably. OpenAI withdrew its own classifier in 2023 after it caught 26% of AI text and flagged 9% of human text, and a Stanford study found detectors biased against non-native English writers. Treat any score as a hint.
Does LinkedIn detect AI-generated posts?
LinkedIn doesn't label AI posts. It lets members flag posts and comments as "Seems like AI slop" and uses those reports, with its own systems, to tune the feed.
What does LinkedIn's "Seems like AI slop" button do?
It sits in the three-dot menu on posts and comments. It tells LinkedIn you think the content is AI slop, which helps tune its feed. LinkedIn says no single report decides how far a post travels.
Does LinkedIn penalise AI posts?
It targets slop, not AI. LinkedIn says people who copy-paste AI-written posts now get about 40% fewer views than before the slop button launched. That's LinkedIn's own figure.
Is it allowed to use AI to write LinkedIn posts?
Yes. LinkedIn's rule is: "It's ok to use AI to help you write, but your posts and comments need to represent your voice and your perspectives."
Are em dashes a sign of AI writing?
A weak one. Models use them a lot, but so do many human writers. Count an em dash only alongside stronger signs like missing specifics.
How do I make sure my own post isn't flagged as AI?
Add a specific only you know, take a clear position, cut template hooks and closers, and write the way you write your comments. A free checker like our LinkedIn AI post detector shows which lines read as templates.
AI disclosure
This article was drafted with AI assistance and edited by Prateek Singh. Every number and quote comes from a source linked in the text, read on 6 November 2026. The example post is illustrative.
Keep reading

Craft
How to Make ChatGPT Write Like You: Every Method in 2026
Every way to make ChatGPT write like you in 2026, with OpenAI's own limits: samples, custom instructions, Memory, Projects, the new Writing Style, and why custom GPTs are retiring. Plus a 20-minute setup and a test.
10 min read
·

Craft
How to Write a LinkedIn Post in 2026: Format, Hook and Length (With Examples)
Where LinkedIn cuts your post at "…more", how to format it for phones, what a study of 248,275 posts says about length, a template you can copy, and five before-and-after rewrites.
10 min read
·

AI and Voice
Why Every AI LinkedIn Post Sounds the Same (and How to Break the Pattern)
AI LinkedIn posts sound the same because general models return the statistical average: safe, agreeable, template-shaped English with no memory of how you write. Here is the template, the tells by model, and the durable fix.
18 min read
·

AI and Voice
Best AI detector in 2026: Originality.ai, GPTZero, ZeroGPT, Copyleaks and Winston AI compared
There is no single best AI detector. Originality.ai suits publishers, GPTZero suits teachers, Copyleaks suits multilingual and institutional checks, and ZeroGPT and Winston AI are the low-cost options. Prices and free tiers were rechecked on 21 October 2026, and every tool still misfires on some human writing, so treat any score as one input.
11 min read
·
From the Twitter algorithm series
The Twitter/X algorithm in May 2026: why voice wins under the new transformer
Read ›