A research checker should tell you two things: which sentences look AI-written and which passages match published work. PaperCheck does both for free, up to 20,000 words per check, 5 checks a week, and shows the result sentence by sentence.
Written by Adithyan, a student who builds PaperCheck. Last updated 2 November 2026.
The copy check looks at arXiv: the papers in your reference list plus related papers found by searching with your paragraphs' key terms. It is not a whole-web check like Turnitin, so a clean result does not prove nothing matches elsewhere.
You can rewrite them yourself, or use the reducer: Rs 30 per paper, it rewrites only the flagged sentences and keeps numbers and citations. The first 1,000 words can be humanized free once per account to see how it reads. See how to fix lines flagged as AI-written.
Yes. You get 5 free checks a week, up to 20,000 words each, with a Google sign-in.
Yes, against arXiv: cited papers plus related papers found by search. It is not a whole-web check.
Not necessarily. PaperCheck gives its own estimate, and Turnitin and other checkers can differ.
Check your paper: 5 free checks
PaperCheck is not affiliated with Turnitin, GPTZero, papercheck.in or papercheck.ai. Scores from any detector are estimates, not proof.