For teachers
When a paper gets flagged
See which passages read as AI-written, then decide what to ask. A flag from our detector is a reason to look closer. It is not proof that anyone cheated.
What the verdicts mean
Human means the part of the paper that reads as machine-written is at or under your setting’s line. Mixed means some of it reads as machine-written or machine-edited. AI means 80% or more of it does. When this site says a paper was flagged, it got Mixed or AI.
Before you talk to the student
Read the marked passages next to the student’s drafts, notes and earlier work. Treat the marks as a reading, not a finding. We have not measured how exactly they fall on the sentences an AI model wrote. Ask the student to walk you through how they wrote those passages. Don’t use a flag as the only reason for a penalty.
- If the flag came from another tool, ask which setting it used and which passages it marked.
What the numbers say
At the standard setting, our detector flagged none of 1,928 human-written papers and essays it was never trained on. For a school checking 10,000 papers, that means no more than about 16 wrongly flagged papers at 95% confidence. At the sensitive setting the ceiling is about 28. This holds only for English academic and student writing like the test set. Every human-written document we tested was written before 2022. Writing from after AI tools became common has not been tested, and neither has writing done with grammar checkers or translation tools.
- In one 960-document test, neither our detector nor a commercial detector flagged any of the 600 written by people.
- Our detector, run v1_8_s2_seed303, standard setting (6%), measured 2026-09-15.
Students learning English
Our detector flagged none of 1,195 essays by English learners kept out of training as a fairness test. They come from one university English language program, written 2005 to 2012. It also flagged none of 600 more it had never scored, from collections whose other essays were partly used in training. That is a count, not proof of fairness.
What it misses
When an AI model lightly polishes a human paper, our detector mostly misses it. Of 39 polished papers, it flagged 3. Paid humanizer tools can hide machine writing from our detector.
- Whether an edit breaks a rule is your school’s policy, not the detector’s.
Pick a setting
Changing the setting never turns an AI verdict into Human. It only moves the line for papers that are partly machine-written.
- Standard (6%, the default) flags a paper when more than a small part of it reads as machine-written.
- Accusation-safe (flags only above 15%) flags a paper only when a substantial part of it reads as machine-written. It removes no false flags, because the default has none, and it calls 10 more AI-edited papers human-written.
- Sensitive (2%) flags at the first small sign, and flagged 2 of 1,928 human documents. Use it to prompt a second look, not a conversation about misconduct.
Short answers
Our detector does not score text under 50 words, and readings under 150 words are weak. A short answer comes back Not scored. It tells you that instead of guessing.
Student work
Human scores the text in memory and does not save it. Neither this site nor our detector keeps a copy of the papers you check.
Read the data privacy FAQA stack of papers
Without an account, one check takes up to 1,200 words. Paste one paper at a time. With a verified school email you get 1,000 papers a month free, up to 25,000 words each. Without one, the Free plan gives you 2,000 words a day.
Read the passages yourself.
Free with a verified school email: 1,000 papers a month.