Plag

Plag is a plagiarism checker and AI detector used by students and educators worldwide to help improve academic writing and reduce the risk of plagiarism. It supports plagiarism detection alongside AI text detection, and offers a readable similarity report to help you understand what needs attention.

Plag’s similarity check compares your document against a large database of scholarly articles and web sources using AI technology. It also supports cross-language (translated) plagiarism detection, so matches can be identified even when content is translated into another language. You can run checks in 129 languages, and the tool can produce a full-document score plus sentence-level breakdowns.

The report includes plagiarism and AI indicators, such as an overall probability score for AI-generated content and matched content results for plagiarism. If you need to act on the findings, you can download a PDF report to share or submit as proof of originality. Plag also accepts multiple input formats (DOC, DOCX, TXT) and plain text paste.

Free use is available: you can upload documents for free and get an overall AI probability score at no cost, as well as plagiarism/AI evaluations (up to three free evaluations). Privacy-first design means your documents are never stored or shared with institutions or third parties, and they are never added to comparative databases.

What does Plag help me check?

Plag checks for plagiarism and also detects AI-generated text. It provides a full document score and a sentence-level breakdown of what’s flagged.

How does Plag perform the similarity check?

Plag uses AI technology to compare your document against a large database of scholarly articles and web sources. It then generates similarity results and scores based on detected matches.

Does Plag detect plagiarism when content is translated into another language?

Yes. Plag includes translated plagiarism detection to help catch matches across languages, not only in English.

What do I get for free?

You can upload documents for free. You can also get up to three free evaluations (plagiarism, AI, and translated plagiarism) and receive a full-document AI probability score at no cost.

Is my document private and safe with Plag?

Your documents are never stored or shared with institutions or third parties, and they are never added to comparative databases.

What file types can I upload to check?

Plag supports DOC, DOCX, and TXT uploads, and it also supports plain text paste. It can also accept other document types mentioned for upload.