Was this written by AI?
Paste any text and this checks how machine-like it reads, sentence by sentence, and shows the signals behind the number. It will also tell you what the result does not prove — because a detection score describes how predictable writing is, not who sat down and wrote it.
A free account includes 10,000 detection words a month — a full essay in one scan. No card.
0 words
Scanning needs a free account — no card, and no ads on any plan.
The limits
A score is not proof of who wrote something.
Detectors disagree with each other, often by a lot. Testing 26 passages against GPTZero, we found the same text scored up to 68 points differently, and ordinary student essays on standard topics came back at 100% AI even though a person could easily have written them.
What the score means
One percentage, three bands. The band matters more than the digit — a 71 and a 78 are the same finding, and treating them as different is how a number starts doing work it cannot support.
Under 35%
The writing varies its rhythm and carries specific detail. This is not a clearance — another detector can and does read the same text differently.
35–65%
Some passages read flat and predictable, others do not. Usually the flat ones are the weaker writing anyway, whoever produced them.
Over 65%
Highly predictable phrasing throughout. Other detectors will very likely agree — including on text a person genuinely wrote.
Where detection fails
This matters more than the score, so it is on the page rather than in a footnote.
- Detectors disagree with each other, sometimes wildly. Across 26 passages we tested against another public detector, the same text came back up to 68 points apart. Both readings cannot be right.
- Ordinary student writing gets flagged. Plain essays on standard school topics came back at 100% AI on another detector, written by people. Writing simply is not evidence of anything.
- Second-language writers are flagged more often. Peer-reviewed testing published in Patterns found seven detectors misclassified 61.22% of essays by non-native English speakers as AI-generated.
- A low score is not a clearance. It predicts very little about what a different tool will say about the same text. The result here is worded to refuse reassurance rather than offer it.
If a score is being used against you and you wrote the work yourself, the score is not evidence. Ask what else the decision rests on.
Who uses it
Teachers and markers
See what a score is made of before you act on one, and read the limits alongside it. A number on its own has ended careers it should not have.
Editors and commissioners
Check submitted copy at the point it arrives, rather than after it publishes.
Writers checking their own work
Find out how your draft reads to a detector before someone else runs it, and see which passages are doing it.
Questions
- Can an AI detector prove who wrote something?
- No, and anyone claiming otherwise is selling you something. A detector measures how predictable text is. Predictable writing is common in people who write plainly, write to a formula, or write in a second language — and all three get flagged. A score is a reason to ask a question, never an answer to one.
- How accurate is it?
- We do not publish a single accuracy figure, because one number across all kinds of writing would be close to meaningless and every vendor quoting one is quoting their best case. What we do publish is how our score relates to another detector's on the same text — including the cases where the two disagree by more than 60 points.
- What happens after my free checks?
- Create a free account and the allowance rises to 10,000 detection words a month — a full essay in a single scan. No card is required for the free account, and there are no ads on any plan.
- Do you keep the text I paste in?
- The privacy policy sets out what is stored and for how long, and the account page lets you delete your account and its data whenever you want.
- Does a low score mean I am safe?
- No. In our own testing, texts we scored below 40 came back from another detector at 44%, 57% and 100%. A low score here predicts very little about what a different tool will say, so we word it to refuse reassurance rather than offer it.
Check a piece of writing now
A free account includes 10,000 detection words a month, with no card and no ads.