AI detector
Review AI signals before you submit.
Analyse writing patterns and review probabilistic AI indicators for the full text and individual passages. Use the result as context, not proof of who wrote the document.
Before interpreting the result
AI detection is probabilistic, not definitive.
An AI detector analyses patterns in the finished text. It does not observe the writing process, identify the person who wrote the document or prove that a particular tool was used.
Human writing can receive a high AI result, and AI-generated writing can receive a low one. Editing, subject matter and writing style can also change the outcome. Use the report as one source of context rather than a final conclusion.
- Probability
- not proof of authorship
- Sentence level
- when detailed indicators are available
- 2 error types
- false positives and false negatives are possible
Inside the AI report
Different metrics show different parts of the result.
AI probability
An overall probability that the analysed text contains patterns associated with AI-generated writing. It is not a percentage of AI-written sentences.
Total AI rate
The share of analysed sentences or fragments marked as likely AI-generated. It may differ from the overall AI probability.
Sentence-level indicators
Review individual sentences or passages when detailed probabilities are available instead of relying only on one document-level result.
How it works
Three steps from text to an AI detection report.
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01
Submit your material.
Paste text, upload a supported file or submit a URL. Each file can be up to 24 MB, and the analysed text must contain at least 100 characters.
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02
Copyleast analyses writing patterns.
The detector evaluates statistical patterns across the text and may calculate document-level and sentence-level AI indicators.
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03
Review the result in context.
Compare AI probability, Total AI rate and highlighted passages. Consider drafts, citations, writing history and the purpose of the document before drawing conclusions.
Who it helps
Built for student writing, useful for careful review.
Students
Review AI-associated patterns in essays and assignments before submission, without treating the result as proof or an automatic problem.
Graduate students & researchers
Examine theses, dissertations, manuscripts and research writing while keeping probabilistic results in context.
Writers & editors
Review documents before publishing or delivery and identify passages that may deserve a closer human read.
Responsible use
An AI score should not decide what happens next.
Copyleast provides probabilistic indicators. It does not prove that AI was used, identify the author or reliably name a specific AI model.
Do not use the result as the sole basis for an academic, disciplinary, employment or legal decision. Review drafts, sources, writing history and other available evidence.
Submitted documents are not used to train AI models or automatically added to the general comparison database. Documents may remain in an account until the user deletes them.
FAQ
AI detection, explained.
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