FAQ
Direct answers to the questions users actually ask — accuracy, AI detection, data handling, and how Noplag differs.
Does Noplag detect AI-generated writing?
Not yet. AI-writing detection is on the roadmap and will ship as a separate signal when it meets our accuracy bar — never silently folded into the plagiarism score. Any tool that claims certainty about AI authorship today is overclaiming; we'd rather be honest about it.
Does Noplag catch paraphrased plagiarism?
The shipped engine detects verbatim and near-verbatim copying — direct copies and lightly edited text. Heavily paraphrased or translated plagiarism is not detected today; paraphrase and semantic layers are on the roadmap. We publish benchmarks that state this plainly instead of hiding it.
My similarity score is high but the text is mine. Why?
The score measures textual overlap, not guilt. Quotes, common phrases, bibliographies, and properly cited passages all match. Open the report, look at what actually matched, and use the match sensitivity filters to exclude short incidental matches and quoted text.
My similarity score is 0% but I'm not sure the text is original.
A 0% score means no verbatim overlap with the corpus Noplag checked against — it is not a certificate of originality. Text plagiarized by heavy rewriting, or copied from a source not in the corpus, won't match.
Is my document added to some database when I check it?
Submitted documents may be added to the Noplag Database, which protects your work from being plagiarized later. You can opt out — see Account and privacy.
Do you train AI on my documents?
No. Never. See Account and privacy.
Can I check a document without an account?
The full product requires an account (free plan available). The open-source engine can be self-hosted with no account at all.
What file types can I upload?
PDF, DOCX, and TXT, up to 10 MB. Scanned PDFs without a text layer can't be checked in the browser — the desktop app can OCR them first.
Can my university/employer see my checks?
No. Your checks are private to your account. Shared reports are visible only to people you give the link to, and links can be revoked.
How is Noplag different from Turnitin?
Turnitin serves institutions; Noplag serves you. Practical differences: individuals can actually buy it, reports show every source so you can verify matches, the detection engine is open source and auditable, and your documents are never used for training. For detailed comparisons see noplag.com/compare.