What happens when you paste an essay in
You paste the essay text into the checker above, and a few seconds later you get a probability that a model wrote the text, the verdict band that probability falls in, and the rate at which that band has been wrong on our evaluation set. If the essay is under 150 words we say so and give no number, since a short piece of text does not carry enough evidence for a call worth making. The essay is scored in memory and not kept once the answer has gone back to you, and there is no account to make first.
If your essay is in Word or a PDF, copy its text into the text box to get an AI-text estimate. The separate file check reads document metadata; it does not extract and score the essay. Metadata can show which software saved a file, but it cannot establish who wrote the words.
Paste your essay as written, keeping its headings and paragraph breaks. Use between 150 and 10000 words. Do not add unrelated material to meet the minimum. A result applies to the submitted text, not to the authorship of every sentence. Keep your drafts and notes if you need to explain how the essay was written.
What the score means on an essay
Read the score alongside the published evaluation rates and verdict outcomes. These describe the tested population and do not establish the probability of AI authorship for your particular essay. On that set the false-positive rate came out at 2.6% on native-speaker writing (13 of 493), which is the share of human texts that got a verdict and were called likely AI all the same, and on writing by people whose first language is not English it was 0.6% (1 of 159). Going the other way, 16.5% of texts we called likely human were actually AI (126 of 764), so a likely-human result is evidence and not a certificate. And 5.8% of our evaluation set (88 of 1522) got no verdict at all, since the scan says inconclusive when the two sides are close and does not pick one.
An essay is the hard case for this kind of software. Careful grammar and a cleaned-up second draft are what a good essay is supposed to have, and they are also the features the models learned to associate with machine output. In 2023 a Stanford group ran TOEFL essays by non-native writers through seven popular tools and more than half came back as machine written [Liang et al., 2023], and a separate test of fourteen tools that year found none of them above 80% accuracy once the conditions changed a little [Weber-Wulff et al., 2023]. So we publish the rates with the counts behind them, and the scan says it cannot tell when it cannot.
What to do with your result
- Likely AI
- Compare the result with drafts, notes and version history. A flag is a reason to review the writing process. It cannot establish misconduct. If it is your work, prepare a record of how you wrote it.
- Inconclusive
- The tool does not have enough evidence for a clear call. Keep that uncertainty in the record. Repeated scans do not establish authorship.
- Likely human
- A likely-human result is evidence and not a certificate. Keep the original essay and its revision history; another detector may disagree.
If you are marking the essay
Use the result the way you would use a colleague's hunch, as a reason to look closer. A likely-AI result on one essay, from one tool, with a false-positive rate that is above zero, is not enough to fail a student on, and the students it lands on most often are the careful ones and the ones writing in a second language. What settles the question is the writing process, so ask for the drafts, the outline and the version history in Google Docs or Word before you say a word about the score. We wrote up what a fair process looks like for this situation, and it is short.
If it is your essay
Run it before you hand it in if that would put your mind at rest, and keep the result with the date on it. It will not make another tool agree with us, since the tools are not calibrated against each other, but it does show that you looked in good faith. What protects you if a question ever comes up is the record of the writing, and that record builds itself when you write in a document with version history switched on. The guide for students goes into this in more detail, and if you have already been flagged, start with the page for that.
Rewriting an essay to pass a scan
We do not sell a humanizer and we do not give advice on getting an essay past a scanner, ours or any other. If you wrote the essay, the drafts are your evidence and you do not need a rewriting tool. If a model wrote it, a tool that reshuffles the sentences turns work you did not do into work you also cannot explain when someone asks you about it. The scan on this site tells you where an essay stands, and that is all it is for.
Sources
- Liang, Yuksekgonul, Mao, Wu, Zou, “GPT detectors are biased against non-native English writers,” Patterns (2023), arxiv.org/abs/2304.02819 — seven detectors, TOEFL essays, 61.3% average false-positive rate.
- Weber-Wulff et al., “Testing of detection tools for AI-generated text,” International Journal for Educational Integrity (2023), arxiv.org/abs/2306.15666 — fourteen tools tested, none above 80% accuracy, and they disagree with each other on the same texts.
Common questions
Is the essay check free, and do I need an account?
It is free and there is no account. Paste your essay into the text box and the result appears on this page. File uploads check metadata separately; they do not score the essay text. The only thing with a daily allowance is the certification badge, and a plain scan does not count against that.
How long does the essay have to be?
At least 150 words, and up to 10,000 words in one scan. Under the floor we give no number at all, since the evidence in a short text is too thin for a verdict we would stand behind, and most school essays are well over it in any case.
Can a teacher fail a student on this result?
Not on the result alone, and we say so on every result card. The score is a probability with a published false-positive rate behind it, which means some human essays will be called likely AI, and the students that happens to most are the careful ones and the ones writing in a second language. What a fair process looks like is on the teachers page.
Will Grammarly or a spell-check push my essay toward likely AI?
We have not measured a slice of Grammarly-polished essays on their own, so we will not put a number on it. The published research on other tools found that polish and formal structure raise the risk of a false positive, and that is a reason to keep your drafts, since a draft history shows the polishing happened on top of your own writing.
Do you keep the essays people paste in?
No. The essay is scored in memory and it is gone once the verdict has gone back to you, and we do not train on it or pass it to anyone else. The privacy page has the details and the tests that keep it true.