About ParaTrace
How detection works, and where it falls short
ParaTrace estimates whether an English text was written by a person or generated by a language model. It gives a fast, explainable second opinion on authorship, from classrooms to newsrooms.
How detection works
- Cleaning. Quotes, dashes and Markdown markers are normalised and invisible characters are removed.
- Splitting. The text is split into overlapping windows of 512 tokens.
- Scoring. Each window is scored by a fine-tuned transformer classifier.
- Averaging. The window scores are averaged into one probability that the text is AI-generated.
- Verdict. The operating point you choose sets the cut-off. A probability at or above it is reported as “likely AI-generated”, below it as “likely human-written”.
Operating points
Every check uses one of two cut-offs. The exact value applied is shown with each result.
- Strict
- Flags text as AI only when confident. About 1 in 100 human texts is wrongly flagged.
- Lenient
- Catches more AI text, but about 1 in 20 human texts is wrongly flagged.
Accuracy and limits
- English only. Texts in other languages are not supported.
- At strict, 0.8 % of held-out human texts (about 1 in 120) were wrongly flagged as AI in our tests. At lenient, about 5 %. Other kinds of writing can differ.
- Persuasive essays written by adults are a known weak spot. About 1 in 4 (24 %) is wrongly flagged at strict.
- Texts under 50 words give less reliable verdicts. In our tests 3.5 % of short human texts were wrongly flagged.
- Long texts are scored in overlapping chunks and the scores are averaged.
This is a statistical estimate, not proof. Don't use it as the sole basis for decisions about a person.
For the full results, including detection by AI developer, false alarms by kind of writing, evasion attacks and speed, read the benchmark report.
Privacy
Texts you submit are stored on our server to operate the service. Don't submit confidential or personal data.
Detection results are held in the service's memory for about 6 hours and may be cleared earlier when the service restarts.
Your password is kept only for this browser tab (in session storage) and is sent with each request. It is removed when you sign out or close the tab.
Getting access
Accounts are issued on request. Request access, and we email your credentials once the request is approved.